mjhjmtu

I did some searches, but unfortunately my question was never answered. The closest question to mine is this: Search for bash command

What I need: A command to search for installed commands using wildcards. Let's say I want to unmount something but forgot the command. I know it contains "mount". So I would do something like this:

searchfor *mount*

To find that unmount is the command I need. I know man -k or yum whatprovides. But that's not what I'm looking for. I want to search for all installed commands (that can be found in the directories provided by the $PATH variable).

My favorite way is to use compgen -c. For example, to find all
commands that contain mount:

$ compgen -c | grep mount
gvfs-mount
mmount
ideviceimagemounter
grub-mount
humount
hmount
umount
mountpoint
mount
fusermount
umount
mount.ntfs
mount.lowntfs-3g
mount.cifs
umount.udisks
mount.nfs
umount.nfs
mount
mount.ntfs-3g
mount.fuse
showmount
rpc.mountd
mountesp
umount.udisks2
mountstats
automount

What's good about compgen -c is that it also finds aliases, user functions and Bash built-in commands, for example:

$ alias aoeuidhtn='echo hi'
$ compgen -c | grep aoeuidhtn
aoeuidhtn
$ my-great-function() printf "Inside great function()n"; 
$ compgen -c | grep great
my-great-function
$ compgen -c | grep '^cd$'
cd

Also, compgen is a part of Bash, so it's always available. As described by help compgen:

Display possible completions depending on the options.

Intended to be used from within a shell function generating possible
completions.  If the optional WORD argument is supplied, matches against
WORD are generated.

Exit Status:

Returns success unless an invalid option is supplied or an error occurs.

#! /bin/bash
s=$1 # e.g. mount
IFS=:
for p in $PATH ; do
 ls "$p/"*"$s"* 2>/dev/null
done

Setting $IFS to : makes the for correctly iterate over the members of $PATH. Redirecting stderr to /dev/null hides error messages for directories that contain no matches.

It can be done in many different ways, look up in $PATH paths, use locate command etc..

 find $(echo $PATH|tr ':' ' ') -maxdepth 1 -name '*mount*' 

This is based choroba's answer, but only uses Bash features (written for GNU Bash 4.3.11). It returns success if any matches are found, failure otherwise.

#!/bin/bash
shopt -s nullglob
s="$1:?" # Error if argument is missing or null.
exit=1 # Return failure unless changed.
IFS=:
for p in $PATH; do
 for f in "$p/"*"$s"*; do
 if [[ -f $f ]]; then
 echo "$f"
 exit=0 # Return success since match found.
 fi
 done
done
exit $exit