Plan 9 from Bell Labs’s /usr/web/sources/plan9/sys/src/cmd/dict/getneeds
#!/bin/rc for (x in spec tag aux status) { grep ' '^$x^' ' $1 > junk1 sort +4 -5 +3n -4 junk1 > junk2 awk '{if ($5 != prev) print $0; prev = $5}' junk2 > junk3 sort -n +2 -3 junk3 > need$x rm junk* }