Zsh keeps a hash of all commands in PATH (updated when you run hash -r and/or twiddle PATH) in a parameter. 

$ for i in ${(onk)commands}; [[ "$i" == *grep* ]] && print $i
bzegrep
bzfgrep
bzgrep
egrep
fgrep
git-grep
grep
grep-changelog
msggrep
pcregrep
podgrep
tcgrep
xml_grep
zegrep
zfgrep
zgrep
zipgrep

[download]

Granted that's a zsh pattern not a regexp (however if you really want to you can compile in pcre support when you build zsh :). Functionalization left as an exercise for the reader.

Update: Ooop, note that that's run with setopt short_loops; without that you'd need the usual shell-y do ... done around the body.

The cake is a lie.
The cake is a lie.
The cake is a lie.

In reply to Re: Finding commands in Unix PATH by Fletch
in thread Finding commands in Unix PATH by toolic

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