examples/scripts.v2/where

   1 #! /bin/bash
   2 #
   3 # original from:
   4 # @(#) where.ksh 1.1 94/07/11
   5 # 91/01/12 john h. dubois iii (john@armory.com)
   6 # 92/08/10 Only print executable *files*.
   7 # 92/10/06 Print err msg if no match found.
   8 # 92/11/27 Added implicit *
   9 # 93/07/23 Print help only if -h is given.
  10 # 94/01/01 Added -x option
  11 # 94/07/11 Don't bother with eval
  12 #
  13 # conversion to bash v2 syntax done by Chet Ramey
  14
  15 name=${0##*/}
  16 Usage="Usage: $name [-hx] 'pattern' ..."
  17 typeset -i exact=0
  18
  19 phelp()
  20 {
  21 echo "$name: find executable files in PATH that match patterns.
  22 $Usage
  23 $name searches each directory specified in the PATH environment variable
  24 for executable files that match the specified patterns.  Patterns are
  25 given as Korn shell filename patterns.  They are surrounded by implicit
  26 '*' characters, so that \"foo\" will match any executble file whose name
  27 contains contains \"foo\".  This can be overridden by using '^' and '$' to
  28 force a match to start at the beginning and end at the end of a filename
  29 respectively.  Characters that are special to the shell must generally
  30 be protected from the shell by surrounding them with quotes.
  31 Examples:
  32 $name foo
  33 lists all executable files in PATH that contain foo.
  34 $name '^b*sh$'
  35 lists all executable files in PATH that start with b and end with sh.
  36 An error message is printed if a no matching file is found for a pattern.
  37 Options:
  38 -h: Print this help.
  39 -x: Find exact matches only; equivalent to putting ^ and $ at the start
  40     and end of each pattern."
  41 }
  42
  43 istrue()
  44 {
  45         test 0 -ne "$1"
  46 }
  47
  48 isfalse()
  49 {
  50         test 0 -eq "$1"
  51 }
  52
  53 while getopts "xh" opt; do
  54         case "$opt" in
  55         x)      exact=1;;
  56         h)      phelp ; exit 0;;
  57         *)      echo -e "$Usage\nUse -h for help." 1>&2; exit 2;;
  58         esac
  59 done
  60
  61 shift $((OPTIND-1))
  62
  63 set +f                  # make sure filename globbing is on
  64 Args=("$@")             # save args
  65
  66 OIFS=$IFS
  67 IFS=:           # Make PATH be split on :
  68 Paths=($PATH)
  69 IFS=$OIFS
  70
  71 for arg in "${Args[@]}"; do
  72
  73     # get rid of leading ^
  74     if istrue $exact; then
  75         arg=${arg}
  76     else
  77             case "$arg" in
  78             ^*) arg=${arg#?};;
  79             *) arg="*$arg" ;;   # Pattern is not anchored at start
  80             esac
  81     fi
  82
  83     # get rid of trailing $
  84     if istrue $exact; then
  85         arg="$arg"
  86     else
  87         case "$arg" in
  88         *\$)    arg=${arg%?} ;;
  89         *)      arg="$arg*" ;;
  90         esac
  91     fi
  92
  93     found=0     # Pattern not found yet
  94     Patterns=
  95     # Make a pattern for each element of PATH
  96     for PathElem in "${Paths[@]}"; do
  97         [ -z "$PathElem" ] && PathElem=.
  98         Patterns="$Patterns $PathElem/$arg"
  99     done
 100
 101     # Find all pattern matches that are executable regular files.
 102     for file in $Patterns; do
 103         if [ -x "$file" ] && [ -f "$file" ]; then
 104             echo "$file"
 105             found=1
 106         fi
 107     done
 108     if [ $found = 0 ]; then
 109         echo "$arg: not found." 1>&2
 110     fi
 111 done