With getppid you can the the PID of the parent process, which is often also the calling process.

Depending on your operating systems, there are probably ways to map that PID to a process name, which might or might not be related to the caller's name.

I'm curious, why do you need that? Maybe there's another way to achieve your goal in a different way.

moritz: OP mentioned a .BAT file. Is getppid implemented on Windows?

OP: If you have any control over the calling script, could you modify it to leave tracks in an environment variable?

moritz: OP mentioned a .BAT file. Is getppid implemented on Windows?

Concluding the operating system from a file extension is a fragile business. I think that mono uses .exe executables on linux.

Also there are a lot of different systems that use .BAT - the difference between DOS 6.0 and Windows 7 are striking.

Perl 6 - links to (nearly) everything that is Perl 6.

OP mentions both bat and shell, which likely means both Windows and Unix. most of the responses reference Windows. sadly, modules for Windows (e.g. Windows::...) can't be used in Unix. it's also likely that wild and crazy modules (though we love 'em) may not be an option. OP could be in a locked down environment where they've got to use what they've got.

If you know it is going to be started from one of these two places, why not have them pass that information in to you?

It is relatively simple (on win, with the right module) to get the parent process id and name, but that isn't going to be very helpful as the name will be cmd.exe! And the command line will be either blank, or however that copy of cmd was started.

This because .bat files are processed by the current running instance of cmd.exe, not a new instance, so the name of the .bat file is never a part of any command line, unless it was start as cmd /c the.bat

I'm curious as to why you need this. This could be an XY Problem.

which is called by either a shell script or a bat file.

Batch files are scripts for the command or cmd shell, meaning they are shell scripts.

use Win32::ToolHelp ':all';
use Win32::Process::CommandLine;
use Tree;

my @nodes;

for (GetProcesses) {
    my %h;
    @h{qw/n_refs pid hid mid n_threads ppid prio flags name/} = @$_;
    Win32::Process::CommandLine::GetPidCommandLine($h{pid}, $h{args});
    push @nodes, Tree->new(\%h);
}

my @forest;

while (my $node = shift @nodes) {
    my ($parent) = grep {$_->value->{pid} == $node->value->{ppid}}
                   @nodes, map $_->traverse, @forest;
    $parent ? $parent->add_child($node) : push @forest, $node;
}

for (map $_->traverse, @forest) {
    printf "%s%s\n",
        "    " x $_->depth,
        $_->value->{args} || $_->value->{name};
}
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Here's a somewhat easier way:

#! perl -slw
use strict;
use Win32::Process::Info;;

my $pi = new Win32::Process::Info;;
my @info = $pi->GetProcInfo( $$ );

my $ppid = $info[0]{ ParentProcessId };
@info = $pi->GetProcInfo( $ppid );

print "Parent process name : ", $info[0]{ ExecutablePath };
print "Command line: ", $info[0]{ CommandLine };
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But as I explained earlier, it's not very useful for the OPs stated requirement as it always gives the same information:

c:\test>type junk.bat
dad

c:\test>junk.bat

c:\test>dad
Parent process name : C:\Windows\System32\cmd.exe
Command line: "C:\Windows\System32\cmd.exe"
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---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

RIP an inspiration; A true Folk's Guy

#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

use Win32::Process::Info;

my $pi = new Win32::Process::Info;;
my @info = $pi->GetProcInfo( $$ );

my $ppid = $info[0]{ ParentProcessId };

# cdarke's addition from here
# tasklist outputs a couple of lines of title junk first
my ($tl_out) = (qx(tasklist /v /fi "PID eq $ppid"))[-1];

# The bat file name is the last "column"
my $parent = (split /\s+/,$tl_out)[-1];

# $parent should now give the bat file name
print "$parent\n";
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