rc/sh/shelly

#!/usr/bin/env perl
### @ shelly
### (perl 5) invoke the first shell found from a list of shells
### as an interactive, non-login shell. arguments are ignored.

use strict;
use Env qw(@PATH);
use File::Spec;

# arbitrary ordering, feel free to change:
my @shells = <zsh osh fish ion bash ash busybox ksh tcsh csh rc dash>;

for my $s (@shells) {
    for my $p (@PATH) {
        #print STDERR "path: $p\n";
        my $fp = File::Spec->join($p, $s);
        my @argv = $s eq "busybox" ? ("sh", "-i") : ($s, "-i");
        if (-d "/C/") {
            # probably Windows.
            exec {"$fp.exe"} @argv if -f "$fp.exe" and -e "$fp.exe";
        } else {
            exec {$fp} @argv if -f $fp and -e $fp;
        }
        #print STDERR "fail: $fp\n";
    }
}

print STDERR "$0: gave up; invoking `sh` without arguments...\n";
exec {"sh"} "sh";