This determines the name/type of shell that the Perl program is running in (i.e. csh, ksh, bash, tsh, etc.).
I ended up writing this because I needed to write to different files based upon the type of shell that the user is running.
#!/usr/bin/perl -w 
use strict;
my $ppid = getppid();
my $shell = `/usr/bin/ps -p $ppid`;
$shell = (split(/\s+/, $shell))[$#_];
print qq(The parent pid is $ppid\n); 
print qq(The name of the parent shell is $shell\n);

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Replies are listed 'Best First'.
Re: What shell am I running?
by rob_au (Abbot) on Nov 17, 2001 at 09:40 UTC
    As others have already pointed out, this code isn't overly portable because of the dependency on the output of ps. A better solution would be to make use of Proc::ProcessTable which I have reviewed previously here. eg.

    #!/usr/bin/perl -w
use strict;
use Proc::ProcessTable;
my $proc = Proc::ProcessTable->new;
foreach (@{$proc->table}) {
    if ($_->pid eq getppid) {
        print "The parent pid is ", getppid, "\n";
        print "The name of the parent shell is ", $_->cmndline, "\n";
    };
};

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    Ooohhh, Rob no beer function well without!

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[d/l]
[select]
Re: What shell am I running?
by blakem (Monsignor) on Nov 17, 2001 at 03:39 UTC
    You're using $#_ improperly here. If I add something like: 
    @_ = ('a','b','c');

    [download]
    before your split line, the split wont return the correct field anymore... Can you see why?

    -Blake

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[d/l]
Re: What shell am I running?
by data64 (Chaplain) on Nov 17, 2001 at 06:20 UTC
    I wonder if someone can come up with a one liner for this.
    Yup, a golf challenge.
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      It's probably not portable, but this works on linux: 
      perl -le 'print$ENV{SHELL}'

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      -Blake

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[d/l]

        You can shave one char off of that; the -l doesn't do anything. Other then that, I think that's as short as it gets for shells that set ${SHELL} (which is POSIX, I think). (Note that the original isn't portable past whatever Unix they were using; ps's format isn't portable at least to my Linux. For that matter, mine doesn't need the -p parameter.)

        Thanks,
        James Mastros,
        Just Another Perl Scribe

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Re: What shell am I running?
by data64 (Chaplain) on Nov 17, 2001 at 06:43 UTC
    Does not work in my cygwin bash shell.
    Is -p a standard parameter to ps ?
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