examples/functions/whatis

   1 #
   2 # whatis -- and implementation of the 10th Edition Unix sh builtin `whatis'
   3 #           command.
   4 #
   5 # usage: whatis arg [...]
   6 #
   7 # For each argument, whatis prints the associated value as a parameter,
   8 # builtin, function, alias, or executable file as appropriate.  In each
   9 # case, the value is printed in a form which would yield the same value
  10 # if typed as input to the shell itself.
  11 #
  12
  13 whatis()
  14 {
  15         local wusage='usage: whatis arg [arg...]'
  16         local fail=0
  17
  18         if [ $# -eq 0 ] ; then
  19                 echo "$wusage"
  20                 return 1
  21         fi
  22
  23         for arg
  24         do
  25                 case $(builtin type -type $arg 2>/dev/null) in
  26                 "alias")
  27                         builtin alias "$arg"
  28                         ;;
  29                 "function")
  30                         builtin type "$arg" | sed 1d
  31                         ;;
  32                 "builtin")
  33                         echo builtin "$arg"
  34                         ;;
  35                 "file")
  36                         builtin type -path "$arg"
  37                         ;;
  38                 *)
  39                         # OK, we could have a variable, or we could have nada
  40                         if [ "$(eval echo \${$arg+set})" = "set" ] ; then
  41                                 # It is a variable, and it is set
  42                                 echo -n "$arg="
  43                                 eval echo '\"'\$$arg'\"'
  44                         else
  45                                 echo whatis: $arg: not found
  46                                 fail=1
  47                         fi
  48                         ;;
  49                 esac
  50         done
  51         return $fail
  52 }