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<h1 align=center>CTAGS</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#SOURCE FILES">SOURCE FILES</a><br>
<a href="#OPTIONS">OPTIONS</a><br>
<a href="#OPERATIONAL DETAILS">OPERATIONAL DETAILS</a><br>
<a href="#TAG FILE FORMAT">TAG FILE FORMAT</a><br>
<a href="#HOW TO USE WITH VI">HOW TO USE WITH VI</a><br>
<a href="#HOW TO USE WITH GNU EMACS">HOW TO USE WITH GNU EMACS</a><br>
<a href="#HOW TO USE WITH NEDIT">HOW TO USE WITH NEDIT</a><br>
<a href="#CAVEATS">CAVEATS</a><br>
<a href="#BUGS">BUGS</a><br>
<a href="#ENVIRONMENT VARIABLES">ENVIRONMENT VARIABLES</a><br>
<a href="#FILES">FILES</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<a href="#AUTHOR">AUTHOR</a><br>
<a href="#MOTIVATION">MOTIVATION</a><br>
<a href="#CREDITS">CREDITS</a><br>
<hr>
<a name="NAME"></a>
<h2>NAME</h2>
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<p>ctags − Generate tag files for source code</p>
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<a name="SYNOPSIS"></a>
<h2>SYNOPSIS</h2>
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<p><b>ctags</b> [<b>options</b>] [<i>file(s)</i>]</p></td>
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<p><b>etags</b> [<b>options</b>] [<i>file(s)</i>]</p></td>
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<a name="DESCRIPTION"></a>
<h2>DESCRIPTION</h2>
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<p>The <b>ctags</b> and <b>etags</b> programs (hereinafter
collectively referred to as <b>ctags</b>, except where
distinguished) generate an index (or "tag") file
for a variety of language objects found in <i>file(s)</i>.
This tag file allows these items to be quickly and easily
located by a text editor or other utility. A "tag"
signifies a language object for which an index entry is
available (or, alternatively, the index entry created for
that object).</p>
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<p>Alternatively, <b>ctags</b> can generate a cross
reference file which lists, in human readable form,
information about the various source objects found in a set
of language files.</p>
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<p>Tag index files are supported by numerous editors, which
allow the user to locate the object associated with a name
appearing in a source file and jump to the file and line
which defines the name. Those known about at the time of
this release are:</p>
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<p><b>Vi</b>(1) and its derivatives (e.g. Elvis, Vim, Vile,
Lemmy), <b>CRiSP</b>, <b>Emacs</b>, <b>FTE</b> (Folding Text
Editor), <b>JED</b>, <b>jEdit</b>, <b>Mined</b>,
<b>NEdit</b> (Nirvana Edit), <b>TSE</b> (The SemWare
Editor), <b>UltraEdit</b>, <b>WorkSpace</b>, <b>X2</b>,
<b>Zeus</b></p></td>
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<p><b>Ctags</b> is capable of generating different kinds of
tags for each of many different languages. For a complete
list of supported languages, the names by which they are
recognized, and the kinds of tags which are generated for
each, see the <b>−−list−languages</b> and
<b>−−list−kinds</b> options.</p>
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<a name="SOURCE FILES"></a>
<h2>SOURCE FILES</h2>
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<p>Unless the <b>−−language−force</b>
option is specified, the language of each source file is
automatically selected based upon a mapping of file names to
languages. The mappings in effect for each language may be
display using the <b>−−list−maps</b>
option and may be changed using the
<b>−−langmap</b> option. On platforms which
support it, if the name of a file is not mapped to a
language and the file is executable, the first line of the
file is checked to see if the file is a "#!"
script for a recognized language.</p>
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<p>By default, all other files names are ignored. This
permits running <b>ctags</b> on all files in either a single
directory (e.g. "ctags *"), or on all files in an
entire source directory tree (e.g. "ctags
−R"), since only those files whose names are
mapped to languages will be scanned.</p>
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<p>[The reason that .h extensions are mapped to C++ files
rather than C files is because it is common to use .h
extensions in C++, and no harm results in treating them as
C++ files.]</p>
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<a name="OPTIONS"></a>
<h2>OPTIONS</h2>
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<p>Despite the wealth of available options, defaults are set
so that <b>ctags</b> is most commonly executed without any
options (e.g. "ctags *", or "ctags
−R"), which will create a tag file in the current
directory for all recognized source files. The options
described below are provided merely to allow custom
tailoring to meet special needs.</p>
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<p>Note that spaces separating the single-letter options
from their parameters are optional.</p>
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<p>Note also that the boolean parameters to the long form
options (those beginning with "−−" and
that take a "<i>[=yes</i>|<i>no]</i>" parameter)
may be omitted, in which case "<b>=</b><i>yes</i>"
is implied. (e.g. <b>−−sort</b> is equivalent to
<b>−−sort</b>=<i>yes</i>). Note further that
"=<i>1</i>" and "=<i>on</i>" are
considered synonyms for "=<i>yes</i>", and that
"=<i>0</i>" and "=<i>off</i>" are
considered synonyms for "=<i>no</i>".</p>
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<p>Some options are either ignored or useful only when used
while running in etags mode (see <b>−e</b> option).
Such options will be noted.</p>
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<p>Most options may appear anywhere on the command line,
affecting only those files which follow the option. A few
options, however, must appear before the first file name and
will be noted as such.</p>
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<p>Options taking language names will accept those names in
either upper or lower case. See the
<b>−−list−languages</b> option for a
complete list of the built-in language names.</p>
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<p><b>−a</b></p>
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<p>Equivalent to <b>−−append</b>.</p>
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<p><b>−B</b></p>
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<p>Use backward searching patterns (e.g. ?pattern?).
[Ignored in etags mode]</p>
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<p><b>−e</b></p>
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<td width="4%"></td>
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<p>Enable etags mode, which will create a tag file for use
with the Emacs editor. Alternatively, if <b>ctags</b> is
invoked by a name containing the string "etags"
(either by renaming, or creating a link to, the executable),
etags mode will be enabled. This option must appear before
the first file name.</p>
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<p><b>−f</b> <i>tagfile</i></p></td>
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<p>Use the name specified by <i>tagfile</i> for the tag file
(default is "tags", or "TAGS" when
running in etags mode). If <i>tagfile</i> is specified as
"−", then the tag file is written to
standard output instead. <b>Ctags</b> will stubbornly refuse
to take orders if <i>tagfile</i> exists and its first line
contains something other than a valid tags line. This will
save your neck if you mistakenly type "ctags −f
*.c", which would otherwise overwrite your first C file
with the tags generated by the rest! It will also refuse to
accept a multi-character file name which begins with a
’−’ (dash) character, since this most
likely means that you left out the tag file name and this
option tried to grab the next option as the file name. If
you really want to name your output tag file
"−ugly", specify it as
"./−ugly". This option must appear before
the first file name. If this option is specified more than
once, only the last will apply.</p>
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<p><b>−F</b></p>
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<p>Use forward searching patterns (e.g. /pattern/)
(default). [Ignored in etags mode]</p>
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<p><b>−h</b> <i>list</i></p></td>
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<p>Specifies a list of file extensions, separated by
periods, which are to be interpreted as include (or header)
files. To indicate files having no extension, use a period
not followed by a non-period character (e.g. ".",
"..x", ".x."). This option only affects
how the scoping of a particular kinds of tags is interpreted
(i.e. whether or not they are considered as globally visible
or visible only within the file in which they are defined);
it does not map the extension to any particular language.
Any tag which is located in a non-include file and cannot be
seen (e.g. linked to) from another file is considered to
have file-limited (e.g. static) scope. No kind of tag
appearing in an include file will be considered to have
file-limited scope. If the first character in the list is a
plus sign, then the extensions in the list will be appended
to the current list; otherwise, the list will replace the
current list. See, also, the
<b>−−file−scope</b> option. The default
list is ".h.H.hh.hpp.hxx.h++.inc.def". To restore
the default list, specify <b>−h</b> <i>default</i>.
Note that if an extension supplied to this option is not
already mapped to a particular language (see <b>SOURCE
FILES</b>, above), you will also need to use either the
<b>−−langmap</b> or
<b>−−language−force</b> option.</p>
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<p><b>−I</b> <i>identifier−list</i></p></td>
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<p>Specifies a list of identifiers which are to be specially
handled while parsing C and C++ source files. This option is
specifically provided to handle special cases arising
through the use of preprocessor macros. When the identifiers
listed are simple identifiers, these identifiers will be
ignored during parsing of the source files. If an identifier
is suffixed with a ’+’ character, <b>ctags</b>
will also ignore any parenthesis-enclosed argument list
which may immediately follow the identifier in the source
files. If two identifiers are separated with the
’=’ character, the first identifiers is replaced
by the second identifiers for parsing purposes. The list of
identifiers may be supplied directly on the command line or
read in from a separate file. If the first character of
<i>identifier−list</i> is ’@’,
’.’ or a pathname separator (’/’ or
’\’), or the first two characters specify a
drive letter (e.g. "C:"), the parameter
<i>identifier−list</i> will be interpreted as a
filename from which to read a list of identifiers, one per
input line. Otherwise, <i>identifier−list</i> is a
list of identifiers (or identifier pairs) to be specially
handled, each delimited by a either a comma or by white
space (in which case the list should be quoted to keep the
entire list as one command line argument). Multiple
<b>−I</b> options may be supplied. To clear the list
of ignore identifiers, supply a single dash
("−") for <i>identifier−list</i>.</p>
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<p>This feature is useful when preprocessor macros are used
in such a way that they cause syntactic confusion due to
their presence. Indeed, this is the best way of working
around a number of problems caused by the presence of
syntax-busting macros in source files (see <b>CAVEATS</b>,
below). Some examples will illustrate this point.</p>
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<p>int foo ARGDECL4(void *, ptr, long int, nbytes)</p></td>
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<p>In the above example, the macro "ARGDECL4"
would be mistakenly interpreted to be the name of the
function instead of the correct name of "foo".
Specifying <b>−I</b> <i>ARGDECL4</i> results in the
correct behavior.</p>
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<p>/* creates an RCS version string in module */</p></td>
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<p>MODULE_VERSION("$Revision: 590 $")</p></td>
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<p>In the above example the macro invocation looks too much
like a function definition because it is not followed by a
semicolon (indeed, it could even be followed by a global
variable definition that would look much like a K&R
style function parameter declaration). In fact, this seeming
function definition could possibly even cause the rest of
the file to be skipped over while trying to complete the
definition. Specifying <b>−I</b>
<i>MODULE_VERSION+</i> would avoid such a problem.</p>
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<p>CLASS Example {<br>
// your content here<br>
};</p></td>
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<p>The example above uses "CLASS" as a
preprocessor macro which expands to something different for
each platform. For instance CLASS may be defined as
"class __declspec(dllexport)" on Win32 platforms
and simply "class" on UNIX. Normally, the absence
of the C++ keyword "class" would cause the source
file to be incorrectly parsed. Correct behavior can be
restored by specifying <b>−I</b>
<i>CLASS=class</i>.</p>
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<p><b>−L</b> <i>file</i></p></td>
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<p>Read from <i>file</i> a list of file names for which tags
should be generated. If <i>file</i> is specified as
"−", then file names are read from standard
input. File names read using this option are processed
following file names appearing on the command line. Options
are also accepted in this input. If this option is specified
more than once, only the last will apply. <b>Note:</b>
<i>file</i> is read in line-oriented mode, where a new line
is the only delimiter and non-trailing white space is
considered significant, in order that file names containing
spaces may be supplied (however, trailing white space is
stripped from lines); this can affect how options are parsed
if included in the input.</p>
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<p><b>−n</b></p>
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<td width="47%">
<p>Equivalent to
<b>−−excmd</b>=<i>number</i>.</p>
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</td>
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<p><b>−N</b></p>
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<td width="47%">
<p>Equivalent to
<b>−−excmd</b>=<i>pattern</i>.</p>
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</td>
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<p><b>−o</b> <i>tagfile</i></p></td>
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<p>Equivalent to <b>−f</b> <i>tagfile</i>.</p>
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<p><b>−R</b></p>
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<p>Equivalent to <b>−−recurse</b>.</p>
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<p><b>−u</b></p>
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<td width="82%">
<p>Equivalent to <b>−−sort</b>=<i>no</i> (i.e.
"unsorted").</p>
</td>
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<td width="3%">
<p><b>−V</b></p>
</td>
<td width="4%"></td>
<td width="82%">
<p>Equivalent to <b>−−verbose</b>.</p>
</td>
<tr valign="top" align="left">
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<td width="3%">
<p><b>−w</b></p>
</td>
<td width="4%"></td>
<td width="82%">
<p>This option is silently ignored for
backward-compatibility with the ctags of SVR4 Unix.</p>
</td>
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<td width="3%">
<p><b>−x</b></p>
</td>
<td width="4%"></td>
<td width="82%">
<p>Print a tabular, human-readable cross reference (xref)
file to standard output instead of generating a tag file.
The information contained in the output includes: the tag
name; the kind of tag; the line number, file name, and
source line (with extra white space condensed) of the file
which defines the tag. No tag file is written and all
options affecting tag file output will be ignored. Example
applications for this feature are generating a listing of
all functions located in a source file (e.g. <b>ctags
−x −−c−kinds</b>=<i>f file</i>), or
generating a list of all externally visible global variables
located in a source file (e.g. <b>ctags −x
−−c−kinds</b>=<i>v</i>
<b>−−file−scope</b>=<i>no file</i>). This
option must appear before the first file name.</p>
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<p><b>−−append</b>[=<i>yes</i>|<i>no</i>]</p></td>
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<p>Indicates whether tags generated from the specified files
should be appended to those already present in the tag file
or should replace them. This option is off by default. This
option must appear before the first file name.</p>
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<p><b>−−etags−include</b>=<i>file</i></p></td>
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<p>Include a reference to <i>file</i> in the tag file. This
option may be specified as many times as desired. This
supports Emacs’ capability to use a tag file which
"includes" other tag files. [Available only in
etags mode]</p>
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</table>
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<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−exclude</b>=[<i>pattern</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Add <i>pattern</i> to a list of excluded files and
directories. This option may be specified as many times as
desired. For each file name considered by <b>ctags</b>, each
<i>pattern</i> specified using this option will be compared
against both the complete path (e.g. some/path/base.ext) and
the base name (e.g. base.ext) of the file, thus allowing
patterns which match a given file name irrespective of its
path, or match only a specific path. If appropriate support
is available from the runtime library of your C compiler,
then <i>pattern</i> may contain the usual shell wildcards
(not regular expressions) common on Unix (be sure to quote
the option parameter to protect the wildcards from being
expanded by the shell before being passed to <b>ctags</b>;
also be aware that wildcards can match the slash character,
’/’). You can determine if shell wildcards are
available on your platform by examining the output of the
<b>−−version</b> option, which will include
"+wildcards" in the compiled feature list;
otherwise, <i>pattern</i> is matched against file names
using a simple textual comparison.</p>
<!-- INDENTATION -->
<p>If <i>pattern</i> begins with the character
’@’, then the rest of the string is interpreted
as a file name from which to read exclusion patterns, one
per line. If <i>pattern</i> is empty, the list of excluded
patterns is cleared. Note that at program startup, the
default exclude list contains "EIFGEN",
"SCCS", "RCS", and "CVS",
which are names of directories for which it is generally not
desirable to descend while processing the
<b>−−recurse</b> option.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−excmd</b>=<i>type</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Determines the type of EX command used to locate tags in
the source file. [Ignored in etags mode]</p>
<!-- INDENTATION -->
<p>The valid values for <i>type</i> (either the entire word
or the first letter is accepted) are:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="10%">
<p><i>number</i></p>
</td>
<td width="4%"></td>
<td width="68%">
<p>Use only line numbers in the tag file for locating tags.
This has four advantages:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="32%"></td>
<td width="3%">
<p>1.</p>
</td>
<td width="3%"></td>
<td width="62%">
<p>Significantly reduces the size of the resulting tag
file.</p>
</td>
<tr valign="top" align="left">
<td width="32%"></td>
<td width="3%">
<p>2.</p>
</td>
<td width="3%"></td>
<td width="62%">
<p>Eliminates failures to find tags because the line
defining the tag has changed, causing the pattern match to
fail (note that some editors, such as <b>vim</b>, are able
to recover in many such instances).</p>
</td>
<tr valign="top" align="left">
<td width="32%"></td>
<td width="3%">
<p>3.</p>
</td>
<td width="3%"></td>
<td width="62%">
<p>Eliminates finding identical matching, but incorrect,
source lines (see <b>BUGS</b>, below).</p>
</td>
<tr valign="top" align="left">
<td width="32%"></td>
<td width="3%">
<p>4.</p>
</td>
<td width="3%"></td>
<td width="62%">
<p>Retains separate entries in the tag file for lines which
are identical in content. In <i>pattern</i> mode, duplicate
entries are dropped because the search patterns they
generate are identical, making the duplicate entries
useless.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="32%"></td>
<td width="68%">
<p>However, this option has one significant drawback:
changes to the source files can cause the line numbers
recorded in the tag file to no longer correspond to the
lines in the source file, causing jumps to some tags to miss
the target definition by one or more lines. Basically, this
option is best used when the source code to which it is
applied is not subject to change. Selecting this option type
causes the following options to be ignored:
<b>−BF</b>.</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="11%">
<p><i>pattern</i></p>
</td>
<td width="3%"></td>
<td width="68%">
<p>Use only search patterns for all tags, rather than the
line numbers usually used for macro definitions. This has
the advantage of not referencing obsolete line numbers when
lines have been added or removed since the tag file was
generated.</p>
</td>
<tr valign="top" align="left">
<td width="18%"></td>
<td width="11%">
<p><i>mixed</i></p>
</td>
<td width="3%"></td>
<td width="68%">
<p>In this mode, patterns are generally used with a few
exceptions. For C, line numbers are used for macro
definition tags. This was the default format generated by
the original <b>ctags</b> and is, therefore, retained as the
default for this option. For Fortran, line numbers are used
for common blocks because their corresponding source lines
are generally identical, making pattern searches useless for
finding all matches.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−extra</b>=<i>[+|−]flags</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies whether to include extra tag entries for
certain kinds of information. The parameter <i>flags</i> is
a set of one-letter flags, each representing one kind of
extra tag entry to include in the tag file. If <i>flags</i>
is preceded by by either the ’+’ or
’−’ character, the effect of each flag is
added to, or removed from, those currently enabled;
otherwise the flags replace any current settings. The
meaning of each flag is as follows:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>f</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Include an entry for the base file name of every source
file (e.g. "example.c"), which addresses the first
line of the file.</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>q</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Include an extra class-qualified tag entry for each tag
which is a member of a class (for languages for which this
information is extracted; currently C++, Eiffel, and Java).
The actual form of the qualified tag depends upon the
language from which the tag was derived (using a form that
is most natural for how qualified calls are specified in the
language). For C++, it is in the form
"class::member"; for Eiffel and Java, it is in the
form "class.member". This may allow easier
location of a specific tags when multiple occurrences of a
tag name occur in the tag file. Note, however, that this
could potentially more than double the size of the tag
file.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−fields</b>=<i>[+|−]flags</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies the available extension fields which are to be
included in the entries of the tag file (see <b>TAG FILE
FORMAT</b>, below, for more information). The parameter
<i>flags</i> is a set of one-letter flags, each representing
one type of extension field to include, with the following
meanings (disabled by default unless indicated):</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>a</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Access (or export) of class members</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>f</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>File-restricted scoping [enabled]</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>i</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Inheritance information</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>k</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Kind of tag as a single letter [enabled]</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>K</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Kind of tag as full name</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>l</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Language of source file containing tag</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>m</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Implementation information</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>n</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Line number of tag definition</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>s</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Scope of tag definition [enabled]</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>S</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Signature of routine (e.g. prototype or parameter
list)</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>z</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Include the "kind:" key in kind field</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>t</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Type and name of a variable or typedef as
"typeref:" field [enabled]</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Each letter or group of letters may be preceded by either
’+’ to add it to the default set, or
’−’ to exclude it. In the absence of any
preceding ’+’ or ’−’ sign,
only those kinds explicitly listed in <i>flags</i> will be
included in the output (i.e. overriding the default set).
This option is ignored if the option
<b>−−format</b>=<i>1</i> has been specified. The
default value of this option is <i>fks</i>.</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−file−scope</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Indicates whether tags scoped only for a single file
(i.e. tags which cannot be seen outside of the file in which
they are defined, such as "static" tags) should be
included in the output. See, also, the <b>−h</b>
option. This option is enabled by default.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−filter</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Causes <b>ctags</b> to behave as a filter, reading source
file names from standard input and printing their tags to
standard output on a file-by-file basis. If
<b>−−sorted</b> is enabled, tags are sorted only
within the source file in which they are defined. File names
are read from standard input in line-oriented input mode
(see note for <b>−L</b> option) and only after file
names listed on the command line or from any file supplied
using the <b>−L</b> option. When this option is
enabled, the options <b>−f</b>, <b>−o</b>, and
<b>−−totals</b> are ignored. This option is
quite esoteric and is disabled by default. This option must
appear before the first file name.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−filter−terminator</b>=<i>string</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies a string to print to standard output following
the tags for each file name parsed when the
<b>−−filter</b> option is enabled. This may
permit an application reading the output of ctags to
determine when the output for each file is finished. Note
that if the file name read is a directory and
<b>−−recurse</b> is enabled, this string will be
printed only one once at the end of all tags found for by
descending the directory. This string will always be
separated from the last tag line for the file by its
terminating newline. This option is quite esoteric and is
empty by default. This option must appear before the first
file name.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−format</b>=<i>level</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Change the format of the output tag file. Currently the
only valid values for <i>level</i> are <i>1</i> or <i>2</i>.
Level 1 specifies the original tag file format and level 2
specifies a new extended format containing extension fields
(but in a manner which retains backward-compatibility with
original <b>vi</b>(1) implementations). The default level is
2. This option must appear before the first file name.
[Ignored in etags mode]</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−help</b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Prints to standard output a detailed usage description,
and then exits.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−if0</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Indicates a preference as to whether code within an
"#if 0" branch of a preprocessor conditional
should be examined for non-macro tags (macro tags are always
included). Because the intent of this construct is to
disable code, the default value of this option is <i>no</i>.
Note that this indicates a preference only and does not
guarantee skipping code within an "#if 0" branch,
since the fall-back algorithm used to generate tags when
preprocessor conditionals are too complex follows all
branches of a conditional. This option is disabled by
default.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−<LANG>−kinds</b>=<i>[+|−]kinds</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies a list of language-specific kinds of tags (or
kinds) to include in the output file for a particular
language, where <b><LANG></b> is case-insensitive and
is one of the built-in language names (see the
<b>−−list−languages</b> option for a
complete list). The parameter <i>kinds</i> is a group of
one-letter flags designating kinds of tags (particular to
the language) to either include or exclude from the output.
The specific sets of flags recognized for each language,
their meanings and defaults may be list using the
<b>−−list−kinds</b> option. Each letter or
group of letters may be preceded by either ’+’
to add it to, or ’−’ to remove it from,
the default set. In the absence of any preceding
’+’ or ’−’ sign, only those
kinds explicitly listed in <i>kinds</i> will be included in
the output (i.e. overriding the default for the specified
language).</p>
<!-- INDENTATION -->
<p>As an example for the C language, in order to add
prototypes and external variable declarations to the default
set of tag kinds, but exclude macros, use
<b>−−c−kinds</b>=<i>+px−d</i>; to
include only tags for functions, use
<b>−−c−kinds</b>=<i>f</i>.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−langdef</b>=<i>name</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Defines a new user-defined language, <i>name</i>, to be
parsed with regular expressions. Once defined, <i>name</i>
may be used in other options taking language names. The
typical use of this option is to first define the language,
then map file names to it using
<i>−−langmap</i>, then specify regular
expressions using
<i>−−regex−<LANG></i> to define how
its tags are found.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−langmap</b>=<i>map[,map[...]]</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Controls how file names are mapped to languages (see the
<b>−−list−maps</b> option). Each
comma-separated <i>map</i> consists of the language name
(either a built-in or user-defined language), a colon, and a
list of file extensions and/or file name patterns. A file
extension is specified by preceding the extension with a
period (e.g. ".c"). A file name pattern is
specified by enclosing the pattern in parentheses (e.g.
"([Mm]akefile)"). If appropriate support is
available from the runtime library of your C compiler, then
the file name pattern may contain the usual shell wildcards
common on Unix (be sure to quote the option parameter to
protect the wildcards from being expanded by the shell
before being passed to <b>ctags</b>). You can determine if
shell wildcards are available on your platform by examining
the output of the <b>−−version</b> option, which
will include "+wildcards" in the compiled feature
list; otherwise, the file name patterns are matched against
file names using a simple textual comparison. When mapping a
file extension, it will first be unmapped from any other
languages.</p>
<!-- INDENTATION -->
<p>If the first character in a map is a plus sign, then the
extensions and file name patterns in that map will be
appended to the current map for that language; otherwise,
the map will replace the current map. For example, to
specify that only files with extensions of .c and .x are to
be treated as C language files, use
"<b>−−langmap</b>=<i>c:.c.x</i>"; to
also add files with extensions of .j as Java language files,
specify
"<b>−−langmap</b>=<i>c:.c.x,java:+.j</i>".
To map makefiles (e.g. files named either
"Makefile", "makefile", or having the
extension ".mak") to a language called
"make", specify
"<b>−−langmap</b>=<i>make:([Mm]akefile).mak</i>".
To map files having no extension, specify a period not
followed by a non-period character (e.g. ".",
"..x", ".x."). To clear the mapping for
a particular language (thus inhibiting automatic generation
of tags for that language), specify an empty extension list
(e.g.
"<b>−−langmap</b>=<i>fortran:</i>").
To restore the default language mappings for all a
particular language, supply the keyword "default"
for the mapping. To specify restore the default language
mappings for all languages, specify
"<b>−−langmap</b>=<i>default</i>".
Note that file extensions are tested before file name
patterns when inferring the language of a file.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−language−force</b>=<i>language</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>By default, <b>ctags</b> automatically selects the
language of a source file, ignoring those files whose
language cannot be determined (see <b>SOURCE FILES</b>,
above). This option forces the specified <i>language</i>
(case-insensitive; either built-in or user-defined) to be
used for every supplied file instead of automatically
selecting the language based upon its extension. In
addition, the special value <i>auto</i> indicates that the
language should be automatically selected (which effectively
disables this option).</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−languages</b>=<i>[+|−]list</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies the languages for which tag generation is
enabled, with <i>list</i> containing a comma-separated list
of language names (case-insensitive; either built-in or
user-defined). If the first language of <i>list</i> is not
preceded by either a ’+’ or
’−’, the current list will be cleared
before adding or removing the languages in <i>list</i>.
Until a ’−’ is encountered, each language
in the list will be added to the current list. As either the
’+’ or ’−’ is encountered in
the list, the languages following it are added or removed
from the current list, respectively. Thus, it becomes simple
to replace the current list with a new one, or to add or
remove languages from the current list. The actual list of
files for which tags will be generated depends upon the
language extension mapping in effect (see the
<b>−−langmap</b> option). Note that all
languages, including user-defined languages are enabled
unless explicitly disabled using this option. Language names
included in <i>list</i> may be any built-in language or one
previously defined with <b>−−langdef</b>. The
default is "all", which is also accepted as a
valid argument. See the
<b>−−list−languages</b> option for a
complete list of the built-in language names.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−license</b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Prints a summary of the software license to standard
output, and then exits.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−line−directives</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Specifies whether "#line" directives should be
recognized. These are present in the output of preprocessors
and contain the line number, and possibly the file name, of
the original source file(s) from which the preprocessor
output file was generated. When enabled, this option will
cause <b>ctags</b> to generate tag entries marked with the
file names and line numbers of their locations original
source file(s), instead of their actual locations in the
preprocessor output. The actual file names placed into the
tag file will have the same leading path components as the
preprocessor output file, since it is assumed that the
original source files are located relative to the
preprocessor output file (unless, of course, the #line
directive specifies an absolute path). This option is off by
default. <b>Note:</b> This option is generally only useful
when used together with the
<b>−−excmd</b>=<i>number</i> (<b>−n</b>)
option. Also, you may have to use either the
<b>−−langmap</b> or
<b>−−language−force</b> option if the
extension of the preprocessor output file is not known to
<b>ctags</b>.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−links</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Indicates whether symbolic links (if supported) should be
followed. When disabled, symbolic links are ignored. This
option is on by default.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−list−kinds</b>[=<i>language</i>|<i>all</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Lists the tag kinds recognized for either the specified
language or all languages, and then exits. Each kind of tag
recorded in the tag file is represented by a one-letter
flag, which is also used to filter the tags placed into the
output through use of the
<b>−−<LANG>−kinds</b> option. Note
that some languages and/or tag kinds may be implemented
using regular expressions and may not be available if regex
support is not compiled into <b>ctags</b> (see the
<b>−−regex−<LANG></b> option). Each
kind listed is enabled unless followed by
"[off]".</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−list−maps</b>[=<i>language</i>|<i>all</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Lists the file extensions and file name patterns which
associate a file name with a language for either the
specified language or all languages, and then exits. See the
<b>−−langmap</b> option, and <b>SOURCE
FILES</b>, above.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−list−languages</b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Lists the names of the languages understood by
<b>ctags</b>, and then exits. These language names are case
insensitive and may be used in the
<b>−−language−force</b>,
<b>−−languages</b>,
<b>−−<LANG>−kinds</b>, and
<b>−−regex−<LANG></b> options.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−options</b>=<i>file</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Read additional options from <i>file</i>. The file should
contain one option per line. As a special case, if
<b>−−options</b>=<i>NONE</i> is specified as the
first option on the command line, it will disable the
automatic reading of any configuration options from either a
file or the environment (see <b>FILES</b>).</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−recurse</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Recurse into directories encountered in the list of
supplied files. If the list of supplied files is empty and
no file list is specified with the <b>−L</b> option,
then the current directory (i.e. ".") is assumed.
Symbolic links are followed. If you don’t like these
behaviors, either explicitly specify the files or pipe the
output of <b>find</b>(1) into <b>ctags −L−</b>
instead. <b>Note:</b> This option is not supported on all
platforms at present. It is available if the output of the
<b>−−help</b> option includes this option. See,
also, the <b>−−exclude</b> to limit
recursion.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−regex−<LANG></b>=<i>/regexp/replacement/[kind−spec/][flags]</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>The <i>/regexp/replacement/</i> pair define a regular
expression replacement pattern, similar in style to
<b>sed</b> substitution commands, with which to generate
tags from source files mapped to the named language,
<b><LANG></b>, (case-insensitive; either a built-in or
user-defined language). The regular expression,
<i>regexp</i>, defines an extended regular expression
(roughly that used by <b>egrep</b>(1)), which is used to
locate a single source line containing a tag and may specify
tab characters using \t. When a matching line is found, a
tag will be generated for the name defined by
<i>replacement</i>, which generally will contain the special
back-references \1 through \9 to refer to matching
sub-expression groups within <i>regexp</i>. The
’/’ separator characters shown in the parameter
to the option can actually be replaced by any character.
Note that whichever separator character is used will have to
be escaped with a backslash (’\’) character
wherever it is used in the parameter as something other than
a separator. The regular expression defined by this option
is added to the current list of regular expressions for the
specified language unless the parameter is omitted, in which
case the current list is cleared.</p>
<!-- INDENTATION -->
<p>Unless modified by <i>flags</i>, <i>regexp</i> is
interpreted as a Posix extended regular expression. The
<i>replacement</i> should expand for all matching lines to a
non-empty string of characters, or a warning message will be
reported. An optional kind specifier for tags matching
<i>regexp</i> may follow <i>replacement</i>, which will
determine what kind of tag is reported in the
"kind" extension field (see <b>TAG FILE
FORMAT</b>, below). The full form of <i>kind−spec</i>
is in the form of a single letter, a comma, a name (without
spaces), a comma, a description, followed by a separator,
which specify the short and long forms of the kind value and
its textual description (displayed using
<b>−−list−kinds</b>). Either the kind name
and/or the description may be omitted. If
<i>kind−spec</i> is omitted, it defaults to
"<i>r,regex</i>". Finally, <i>flags</i> are one or
more single-letter characters having the following effect
upon the interpretation of <i>regexp</i>:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>b</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>The pattern is interpreted as a Posix basic regular
expression.</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>e</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>The pattern is interpreted as a Posix extended regular
expression (default).</p>
</td>
<tr valign="top" align="left">
<td width="23%"></td>
<td width="2%">
<p><i>i</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>The regular expression is to be applied in a
case-insensitive manner.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Note that this option is available only if <b>ctags</b>
was compiled with support for regular expressions, which
depends upon your platform. You can determine if support for
regular expressions is compiled in by examining the output
of the <b>−−version</b> option, which will
include "+regex" in the compiled feature list.</p>
<!-- INDENTATION -->
<p>For more information on the regular expressions used by
<b>ctags</b>, see either the <b>regex(5,7)</b> man page, or
the GNU info documentation for regex (e.g. "info
regex").</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−sort</b>[=<i>yes</i>|<i>no</i>|<i>foldcase</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Indicates whether the tag file should be sorted on the
tag name (default is <i>yes</i>). Note that the original
<b>vi</b>(1) required sorted tags. The <i>foldcase</i> value
specifies case insensitive (or case-folded) sorting. Fast
binary searches of tag files sorted with case-folding will
require special support from tools using tag files, such as
that found in the ctags readtags library, or Vim version 6.2
or higher (using "set ignorecase"). This option
must appear before the first file name. [Ignored in etags
mode]</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−tag−relative</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Indicates that the file paths recorded in the tag file
should be relative to the directory containing the tag file,
rather than relative to the current directory, unless the
files supplied on the command line are specified with
absolute paths. This option must appear before the first
file name. The default is <i>yes</i> when running in etags
mode (see the <b>−e</b> option), <i>no</i>
otherwise.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−totals</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Prints statistics about the source files read and the tag
file written during the current invocation of <b>ctags</b>.
This option is off by default. This option must appear
before the first file name.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−verbose</b>[=<i>yes</i>|<i>no</i>]</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Enable verbose mode. This prints out information on
option processing and a brief message describing what action
is being taken for each file considered by <b>ctags</b>.
Normally, <b>ctags</b> does not read command line arguments
until after options are read from the configuration files
(see <b>FILES</b>, below) and the <b>CTAGS</b> environment
variable. However, if this option is the first argument on
the command line, it will take effect before any options are
read from these sources. The default is <i>no</i>.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>−−version</b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="18%"></td>
<td width="82%">
<p>Prints a version identifier for <b>ctags</b> to standard
output, and then exits. This is guaranteed to always contain
the string "Exuberant Ctags".</p>
</td>
</table>
<a name="OPERATIONAL DETAILS"></a>
<h2>OPERATIONAL DETAILS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>As <b>ctags</b> considers each file name in turn, it
tries to determine the language of the file by applying the
following three tests in order: if the file extension has
been mapped to a language, if the file name matches a shell
pattern mapped to a language, and finally if the file is
executable and its first line specifies an interpreter using
the Unix-style "#!" specification (if supported on
the platform). If a language was identified, the file is
opened and then the appropriate language parser is called to
operate on the currently open file. The parser parses
through the file and adds an entry to the tag file for each
language object it is written to handle. See <b>TAG FILE
FORMAT</b>, below, for details on these entries.</p>
<!-- INDENTATION -->
<p>This implementation of <b>ctags</b> imposes no formatting
requirements on C code as do legacy implementations. Older
implementations of ctags tended to rely upon certain
formatting assumptions in order to help it resolve coding
dilemmas caused by preprocessor conditionals.</p>
<!-- INDENTATION -->
<p>In general, <b>ctags</b> tries to be smart about
conditional preprocessor directives. If a preprocessor
conditional is encountered within a statement which defines
a tag, <b>ctags</b> follows only the first branch of that
conditional (except in the special case of "#if
0", in which case it follows only the last branch). The
reason for this is that failing to pursue only one branch
can result in ambiguous syntax, as in the following
example:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>#ifdef TWO_ALTERNATIVES<br>
struct {<br>
#else<br>
union {<br>
#endif</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="28%"></td>
<td width="72%">
<p>short a;<br>
long b;</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>}</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Both branches cannot be followed, or braces become
unbalanced and <b>ctags</b> would be unable to make sense of
the syntax.</p>
<!-- INDENTATION -->
<p>If the application of this heuristic fails to properly
parse a file, generally due to complicated and inconsistent
pairing within the conditionals, <b>ctags</b> will retry the
file using a different heuristic which does not selectively
follow conditional preprocessor branches, but instead falls
back to relying upon a closing brace ("}") in
column 1 as indicating the end of a block once any brace
imbalance results from following a #if conditional
branch.</p>
<!-- INDENTATION -->
<p><b>Ctags</b> will also try to specially handle arguments
lists enclosed in double sets of parentheses in order to
accept the following conditional construct:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>extern void foo __ARGS((int one, char two));</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Any name immediately preceding the "((" will be
automatically ignored and the previous name will be
used.</p>
<!-- INDENTATION -->
<p>C++ operator definitions are specially handled. In order
for consistency with all types of operators (overloaded and
conversion), the operator name in the tag file will always
be preceded by the string "operator " (i.e. even
if the actual operator definition was written as
"operator<<").</p>
<!-- INDENTATION -->
<p>After creating or appending to the tag file, it is sorted
by the tag name, removing identical tag lines.</p>
</td>
</table>
<a name="TAG FILE FORMAT"></a>
<h2>TAG FILE FORMAT</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>When not running in etags mode, each entry in the tag
file consists of a separate line, each looking like this in
the most general case:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="12%"></td>
<td width="88%">
<p>tag_name<TAB>file_name<TAB>ex_cmd;"<TAB>extension_fields</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>The fields and separators of these lines are specified as
follows:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="17%"></td>
<td width="3%">
<p>1.</p>
</td>
<td width="3%"></td>
<td width="77%">
<p>tag name</p>
</td>
<tr valign="top" align="left">
<td width="17%"></td>
<td width="3%">
<p>2.</p>
</td>
<td width="3%"></td>
<td width="77%">
<p>single tab character</p>
</td>
<tr valign="top" align="left">
<td width="17%"></td>
<td width="3%">
<p>3.</p>
</td>
<td width="3%"></td>
<td width="77%">
<p>name of the file in which the object associated with the
tag is located</p>
</td>
<tr valign="top" align="left">
<td width="17%"></td>
<td width="3%">
<p>4.</p>
</td>
<td width="3%"></td>
<td width="77%">
<p>single tab character</p>
</td>
<tr valign="top" align="left">
<td width="17%"></td>
<td width="3%">
<p>5.</p>
</td>
<td width="3%"></td>
<td width="77%">
<p>EX command used to locate the tag within the file;
generally a search pattern (either /pattern/ or ?pattern?)
or line number (see <b>−−excmd</b>). Tag file
format 2 (see <b>−−format</b>) extends this EX
command under certain circumstances to include a set of
extension fields (described below) embedded in an EX comment
immediately appended to the EX command, which leaves it
backward-compatible with original <b>vi</b>(1)
implementations.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>A few special tags are written into the tag file for
internal purposes. These tags are composed in such a way
that they always sort to the top of the file. Therefore, the
first two characters of these tags are used a magic number
to detect a tag file for purposes of determining whether a
valid tag file is being overwritten rather than a source
file.</p>
<!-- INDENTATION -->
<p>Note that the name of each source file will be recorded
in the tag file exactly as it appears on the command line.
Therefore, if the path you specified on the command line was
relative to the current directory, then it will be recorded
in that same manner in the tag file. See, however, the
<b>−−tag−relative</b> option for how this
behavior can be modified.</p>
<!-- INDENTATION -->
<p>Extension fields are tab-separated key-value pairs
appended to the end of the EX command as a comment, as
described above. These key value pairs appear in the general
form "<i>key</i>:<i>value</i>". Their presence in
the lines of the tag file are controlled by the
<b>−−fields</b> option. The possible keys and
the meaning of their values are as follows:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><i>access</i></p>
</td>
<td width="9%"></td>
<td width="71%">
<p>Indicates the visibility of this class member, where
<i>value</i> is specific to the language.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><i>file</i></p>
</td>
<td width="9%"></td>
<td width="71%">
<p>Indicates that the tag has file-limited visibility. This
key has no corresponding value.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><i>kind</i></p>
</td>
<td width="9%"></td>
<td width="71%">
<p>Indicates the type, or kind, of tag. Its value is either
one of the corresponding one-letter flags described under
the various <b>−−<LANG>−kinds</b>
options above, or a full name. It is permitted (and is, in
fact, the default) for the key portion of this field to be
omitted. The optional behaviors are controlled with the
<b>−−fields</b> option.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><i>implementation</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="29%"></td>
<td width="71%">
<p>When present, this indicates a limited implementation
(abstract vs. concrete) of a routine or class, where
<i>value</i> is specific to the language
("virtual" or "pure virtual" for C++;
"abstract" for Java).</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><i>inherits</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>When present, <i>value</i>. is a comma-separated list of
classes from which this class is derived (i.e. inherits
from).</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><i>signature</i></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>When present, <i>value</i> is a language-dependent
representation of the signature of a routine. A routine
signature in its complete form specifies the return type of
a routine and its formal argument list. This extension field
is presently supported only for C-based languages and does
not include the return type.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>In addition, information on the scope of the tag
definition may be available, with the key portion equal to
some language-dependent construct name and its value the
name declared for that construct in the program. This scope
entry indicates the scope in which the tag was found. For
example, a tag generated for a C structure member would have
a scope looking like "struct:myStruct".</p>
</td>
</table>
<a name="HOW TO USE WITH VI"></a>
<h2>HOW TO USE WITH VI</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Vi will, by default, expect a tag file by the name
"tags" in the current directory. Once the tag file
is built, the following commands exercise the tag indexing
feature:</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><b>vi −t tag</b></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Start vi and position the cursor at the file and line
where "tag" is defined.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><b>:ta tag</b></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Find a tag.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><b>Ctrl-]</b></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Find the tag under the cursor.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="14%">
<p><b>Ctrl-T</b></p>
</td>
<td width="4%"></td>
<td width="71%">
<p>Return to previous location before jump to tag (not
widely implemented).</p>
</td>
</table>
<a name="HOW TO USE WITH GNU EMACS"></a>
<h2>HOW TO USE WITH GNU EMACS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Emacs will, by default, expect a tag file by the name
"TAGS" in the current directory. Once the tag file
is built, the following commands exercise the tag indexing
feature:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>M-x visit−tags−table <RET> FILE
<RET></b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="26%"></td>
<td width="74%">
<p>Select the tag file, "FILE", to use.</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>M-. [TAG] <RET></b></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="26%"></td>
<td width="74%">
<p>Find the first definition of TAG. The default tag is the
identifier under the cursor.</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="5" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="11%">
<p><b>M-*</b></p>
</td>
<td width="4%"></td>
<td width="72%">
<p>Pop back to where you previously invoked
"M-.".</p>
</td>
<td width="2%">
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="11%">
<p><b>C-u M-.</b></p>
</td>
<td width="4%"></td>
<td width="72%">
<p>Find the next definition for the last tag.</p>
</td>
<td width="2%">
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>For more commands, see the <i>Tags</i> topic in the Emacs
info document.</p>
</td>
</table>
<a name="HOW TO USE WITH NEDIT"></a>
<h2>HOW TO USE WITH NEDIT</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>NEdit version 5.1 and later can handle the new extended
tag file format (see <b>−−format</b>). To make
NEdit use the tag file, select "File−>Load
Tags File". To jump to the definition for a tag,
highlight the word, the press Ctrl-D. NEdit 5.1 can can read
multiple tag files from different directories. Setting the X
resource nedit.tagFile to the name of a tag file instructs
NEdit to automatically load that tag file at startup
time.</p>
</td>
</table>
<a name="CAVEATS"></a>
<h2>CAVEATS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Because <b>ctags</b> is neither a preprocessor nor a
compiler, use of preprocessor macros can fool <b>ctags</b>
into either missing tags or improperly generating
inappropriate tags. Although <b>ctags</b> has been designed
to handle certain common cases, this is the single biggest
cause of reported problems. In particular, the use of
preprocessor constructs which alter the textual syntax of C
can fool <b>ctags</b>. You can work around many such
problems by using the <b>−I</b> option.</p>
<!-- INDENTATION -->
<p>Note that since <b>ctags</b> generates patterns for
locating tags (see the <b>−−excmd</b> option),
it is entirely possible that the wrong line may be found by
your editor if there exists another source line which is
identical to the line containing the tag. The following
example demonstrates this condition:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>int variable;</p>
<!-- INDENTATION -->
<p>/* ... */<br>
void foo(variable)<br>
int variable;<br>
{</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="28%"></td>
<td width="72%">
<p>/* ... */</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>}</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Depending upon which editor you use and where in the code
you happen to be, it is possible that the search pattern may
locate the local parameter declaration in foo() before it
finds the actual global variable definition, since the lines
(and therefore their search patterns are identical). This
can be avoided by use of the
<b>−−excmd</b>=<i>n</i> option.</p>
</td>
</table>
<a name="BUGS"></a>
<h2>BUGS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><b>Ctags</b> has more options than <b>ls</b>(1).</p>
<!-- INDENTATION -->
<p>When parsing a C++ member function definition (e.g.
"className::function"), <b>ctags</b> cannot
determine whether the scope specifier is a class name or a
namespace specifier and always lists it as a class name in
the scope portion of the extension fields. Also, if a C++
function is defined outside of the class declaration (the
usual case), the access specification (i.e. public,
protected, or private) and implementation information (e.g.
virtual, pure virtual) contained in the function declaration
are not known when the tag is generated for the function
definition. It will, however be available for prototypes
(e.g <b>−−c++−kinds</b>=<i>+p</i>).</p>
<!-- INDENTATION -->
<p>No qualified tags are generated for language objects
inherited into a class.</p>
</td>
</table>
<a name="ENVIRONMENT VARIABLES"></a>
<h2>ENVIRONMENT VARIABLES</h2>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="4" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><b>CTAGS</b></p>
</td>
<td width="3%"></td>
<td width="77%">
<p>If this environment variable exists, it will be expected
to contain a set of default options which are read when
<b>ctags</b> starts, after the configuration files listed in
<b>FILES</b>, below, are read, but before any command line
options are read. Options appearing on the command line will
override options specified in this variable. Only options
will be read from this variable. Note that all white space
in this variable is considered a separator, making it
impossible to pass an option parameter containing an
embedded space. If this is a problem, use a configuration
file instead.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><b>ETAGS</b></p>
</td>
<td width="3%"></td>
<td width="77%">
<p>Similar to the <b>CTAGS</b> variable above, this
variable, if found, will be read when <b>etags</b> starts.
If this variable is not found, <b>etags</b> will try to use
<b>CTAGS</b> instead.</p>
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p><b>TMPDIR</b></p>
</td>
<td width="3%"></td>
<td width="77%">
<p>On Unix-like hosts where mkstemp() is available, the
value of this variable specifies the directory in which to
place temporary files. This can be useful if the size of a
temporary file becomes too large to fit on the partition
holding the default temporary directory defined at
compilation time. <b>ctags</b> creates temporary files only
if either (1) an emacs-style tag file is being generated,
(2) the tag file is being sent to standard output, or (3)
the program was compiled to use an internal sort algorithm
to sort the tag files instead of the the sort utility of the
operating system. If the sort utility of the operating
system is being used, it will generally observe this
variable also. Note that if <b>ctags</b> is setuid, the
value of TMPDIR will be ignored.</p>
</td>
</table>
<a name="FILES"></a>
<h2>FILES</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p><i>/ctags.cnf (on MSDOS, MSWindows only)<br>
/etc/ctags.conf<br>
/usr/local/etc/ctags.conf<br>
$HOME/.ctags<br>
$HOME/ctags.cnf (on MSDOS, MSWindows only)<br>
.ctags<br>
ctags.cnf (on MSDOS, MSWindows only)</i></p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>If any of these configuration files exist, each will be
expected to contain a set of default options which are read
in the order listed when <b>ctags</b> starts, but before the
<b>CTAGS</b> environment variable is read or any command
line options are read. This makes it possible to set up
site-wide, personal or project-level defaults. It is
possible to compile <b>ctags</b> to read an additional
configuration file before any of those shown above, which
will be indicated if the output produced by the
<b>−−version</b> option lists the
"custom-conf" feature. Options appearing in the
<b>CTAGS</b> environment variable or on the command line
will override options specified in these files. Only options
will be read from these files. Note that the option files
are read in line-oriented mode in which spaces are
significant (since shell quoting is not possible). Each line
of the file is read as one command line parameter (as if it
were quoted with single quotes). Therefore, use new lines to
indicate separate command-line arguments.</p>
</td>
</table>
<!-- TABS -->
<table width="100%" border=0 rules="none" frame="void"
cols="5" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="6%">
<p><i>tags</i></p>
</td>
<td width="5%"></td>
<td width="58%">
<p>The default tag file created by <b>ctags</b>.</p>
</td>
<td width="20%">
</td>
<tr valign="top" align="left">
<td width="11%"></td>
<td width="6%">
<p><i>TAGS</i></p>
</td>
<td width="5%"></td>
<td width="58%">
<p>The default tag file created by <b>etags</b>.</p>
</td>
<td width="20%">
</td>
</table>
<a name="SEE ALSO"></a>
<h2>SEE ALSO</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>The official Exuberant Ctags web site at:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>http://ctags.sourceforge.net</p></td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Also <b>ex</b>(1), <b>vi</b>(1), <b>elvis</b>, or, better
yet, <b>vim</b>, the official editor of <b>ctags</b>. For
more information on <b>vim</b>, see the VIM Pages web site
at:</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>http://www.vim.org/</p></td>
</table>
<a name="AUTHOR"></a>
<h2>AUTHOR</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>Darren Hiebert <dhiebert at
users.sourceforge.net><br>
http://DarrenHiebert.com/</p>
</td>
</table>
<a name="MOTIVATION"></a>
<h2>MOTIVATION</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>"Think ye at all times of rendering some service to
every member of the human race."</p>
<!-- INDENTATION -->
<p>"All effort and exertion put forth by man from the
fullness of his heart is worship, if it is prompted by the
highest motives and the will to do service to
humanity."</p>
</td>
</table>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="22%"></td>
<td width="78%">
<p>−− From the Baha’i Writings</p></td>
</table>
<a name="CREDITS"></a>
<h2>CREDITS</h2>
<!-- INDENTATION -->
<table width="100%" border=0 rules="none" frame="void"
cols="2" cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="89%">
<p>This version of <b>ctags</b> was originally derived from
and inspired by the ctags program by Steve Kirkendall
<[email protected]> that comes with the Elvis vi
clone (though virtually none of the original code
remains).</p>
<!-- INDENTATION -->
<p>Credit is also due Bram Moolenaar <[email protected]>,
the author of <b>vim</b>, who has devoted so much of his
time and energy both to developing the editor as a service
to others, and to helping the orphans of Uganda.</p>
<!-- INDENTATION -->
<p>The section entitled "HOW TO USE WITH GNU
EMACS" was shamelessly stolen from the info page for
GNU <b>etags</b>.</p>
</td>
</table>
<hr>
</body>
</html>
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