Perl never sees the redirection. The redirection is handled by the shell invoking your program.

If you just want to launch another program as if it were your program, see exec.

Otherwise, maybe you can tell us what you want to achieve, then we can maybe give you a better way of getting there.

The shell does not pass the command you gave it to the applications it launches as a result. (Not at all in unix, and only partially in Windows.)

• Note that one command can launch multiple applications.
• Note that there might not even be a shell involved, in which case there wouldn't even be a shell command.
• Note that all shells don't use the same syntax for their commands.

Clearly, you're barking up the wrong tree. What problem are you actually trying to solve?

As noted, you can get your commandline arguments, except for IO redirection, via @ARGV.

Whatever IO redirection has been specified is available within your Perl script via STDIN, STDOUT and STDERR.

Here's how you can get at the filenames:

$ perl -wE 'use IO::Handle; my $inode = (*STDERR{IO}->stat)[1]; say `f
+ind -inum $inode`;' 2> derf
./derf

$ perl -wE 'use IO::Handle; my $inode = (*STDOUT{IO}->stat)[1]; say `f
+ind -inum $inode`;' > fred; cat fred
./fred
[download]

That obviously needs substantial error checking and other work for a serious script but hopefully it's at least a start in right direction.

I have a script that will stay in the background and handle a loop every minute. In the past, I've had trouble with some scripts having memory issues after running like this for too long, so I figured one easy way to handle it would be to grab the command line when first run and save it, then after a few hours, just exec() that same line and die, leaving a new instance running.

It was just an idea of a new way to be lazy (hey, doesn't Larry Wall encourage that?), rather than checking individually for each argument and reconstructing the command line and perhaps trying to reconstruct any IO redirection as well. It's not a "have to" thing, just an idea that it seems clear won't work.

I know I can use a loop in a Perl or bash script to just relaunch every time the program dies, but I figured this might be more self contained.

Since it's not something I can count on, there are other ways to do it. I just thought it might lead to some easy and possibly interesting little tricks of it could work.

Thanks for the help on this!

Won't this pretty much do what you're asking for?:

...
if( some condition ) {
##    fork and exit; ## Update: redundant
    exec $^X, $0, @ARGV;
}
[download]

I was hoping to also get anything like IO redirection, but I see from other responses that's not possible. Otherwise, it would do it. Thanks.