use of <STDOUT>

PerlZealot has asked for the wisdom of the Perl Monks concerning the following question:

Hi everyone!!! I want to write a little sub that takes the output from: system(pwd); and stores it in a variable. Here's my code:

#!/usr/bin/env perl

sub dirgets()
{
  my $dirval;
  system(pwd);
  $dirval = <STDOUT>;
  return($dirval);
}

my $name;
$name = &dirgets();
[download]

The problem is that I don't seem to get a value from this. Sure, pwd does its thing, but "dirgets" does not. What am I messing up?

Comment on use of <STDOUT> Select or Download Code

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Re: use of <STDOUT> by locked_user sundialsvc4 (Abbot) on Mar 06, 2008 at 22:15 UTC
How about just using back-tick? return `pwd`; Since this sort of thing is done so often, the "back-tick" quote-mark causes the enclosing command to be executed and the result returned as a character string. Your entire subroutine becomes ... unnecessary. `:-O` On my keyboard, this character (along with tilde "~") is located on the upper-left side, to the left of the numeral-"1" key. “This is Perl. There is more than one way to do it.™ ”
Re^2: use of <STDOUT> by Fletch (Bishop) on Mar 06, 2008 at 23:11 UTC
And some of the ways don't involve calling an external utility; c.f. Cwd, POSIX (specifically `getcwd` therein). The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l]
Re^3: use of <STDOUT> by PerlZealot (Acolyte) on Mar 06, 2008 at 23:42 UTC
I would normally use cwd(). Strangely, when I am running the Perl interpreter that comes with cygwin installation, cwd() never seems to return anything...	[reply]
Re: use of <STDOUT> by igelkott (Priest) on Mar 06, 2008 at 22:19 UTC
Use backticks $dirval = `pwd` or `open(P, "pwd \|")`.	[reply] [d/l] [select]
Re: use of <STDOUT> by TGI (Parson) on Mar 06, 2008 at 23:34 UTC
If you just want the current directory, use core module Cwd. `use Cwd; print cwd;` [download] TGI says moo	[reply] [d/l]
Re: use of <STDOUT> by halfcountplus (Hermit) on Mar 07, 2008 at 13:24 UTC
Don't use system, use open with a pipe (avoiding <STDOUT>): #!/usr/bin/perl use strict; my $dir; open(SYS, "pwd \|"); while (<SYS>) {$dir=$_; last;} chomp $dir; print $dir; Incidentally, if you use my $pid = open(SYS, "pwd \|") you get the process number of "pwd" in a variable. I presume there is no need to close(SYS) but someone may know better.	[reply]