#!/bin/bash
## WH 1998 FEB 19, 2001 Jan 15
## This is a variant on ksh's "whence -p" and "type"=whence -v and csh's "which".  
## This variant lists **all** files in $PATH that match a file **pattern**.
## Utility "find" is not really appropriate for this.

## Using full path names below to guard against bad PATH.
## Using bash instead of sh, since sh does not handle empty argument 
##  list to "set" correctly.

usage()
{
	echo >&2 "Usage: ${0##*/} [-m] [-s] [-p <path>] [--] 'blank-free file pattern'"
	/bin/cat >&2 <<\EOF
  Find all files on PATH (in same order) matching the file pattern.  
  Use ' quotes to protect the pattern if it contains wildcards.
  -p <path>: Use the colon separated list of directories <path> instead of PATH
  -m:  Search for manual entries by using MANPATH instead of PATH and 
         treating the pattern as  man*/pattern.*
  -s:  Use a sane internal setting for PATH and MANPATH
  --:  Use this option if pattern starts with a -
EOF
	exit 1
}


man=no
sane=no
path="$PATH"

while getopts :msp: opt
do
        case $opt in
        m)      man=yes
                path="$MANPATH"
                ;;
        s)      sane=yes  ;;
        p)      path="$OPTARG" ;;
        \?|:)  	echo >&2 "Error: Bad option $OPTARG or missing argument."
                usage ;;
        *)     	usage ;;
        esac
done
shift $(( OPTIND - 1 ))
 
if [ $sane = yes ] ; then
	if [[ $man = yes ]] ; then
		path=/usr/man:/usr/local/man
	else
		path=/usr/bin:$HOME/bin:/usr/local/bin:.
	fi
fi


if [ $# != 1 ] ; then
	usage
fi

## set pattern
if [ $man = no ] ; then
	pattern="$1"
else
	pattern="man*/$1.*"
fi

## Set arguments to be the path components with colons removed.
## However, PATH=:/bin::/:  means PATH=.:/bin:.:/:.  so the first three 
## sed replacements just put these implicit periods back in.  
## If PATH=:/bin::/: then $1 to $5 will be set to:   .  /bin  .  /  .

export path

set -- `/bin/echo $path | 
   /bin/sed -e 's/^:/.:/g' -e 's/:$/:./g' -e 's/::/:.:/g' -e 's/:/ /g'`


## list files matching pattern

for dir
do
  /bin/ls -1d $dir/$pattern 2>/dev/null ## suppress error "no file matches"
done

exit 0