#!/usr/bin/perl -w
use strict;

# inpath - verify that a specified program is either valid as-is,
#   or can be found in the PATH directory list.

sub in_path {
  my ($cmd, $path) = @_;
  my $found = 0;
  foreach my $directory (split /:/, $path) {
    return "exe" if -x "$directory/$cmd";
    $found = 1 if -e "$directory/$cmd";
  }
  return $found ? "plain" : "not found";
}

sub check_for_command_in_path {
  my ($command) = @_;

  if ($command =~ m{^/}) {
    return 'exe' if -x $command;
    return -e $command ? 'plain' : 'not found';
  } else {
     in_path($command, $ENV{PATH});
  }
}

die "Usage: $0 command\n" if @ARGV != 1;

my $ret = check_for_command_in_path($ARGV[0]);
print "Executable $ARGV[0] found in PATH\n"  if $ret eq "exe";
print "$ARGV[0] found but not executable"    if $ret eq "plain";
print "$ARGV[0] not found in PATH\n"         if $ret eq "not found";