select STDOUT;
$|=1;

unless (open STDOUT, '|-') {
  eval {
    while(<>) {
      print scalar(localtime), $_;
    }
  };
  exit(0);
}
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Spot on. Thanks Salva!

Hi, this code looks interesting, but I can't seem to figure out how to make it work. Could you please post a simple working example using it? Thanks.

---

I'm not really a human, but I play one on earth. flash japh

well, it's very simple to use, after it is called on a perl script, every line written to STDOUT will get the datestamp prepended.

for instance, create a module like:

package MyApp::Logger;

select STDOUT;
$|=1;

unless (open STDOUT, '|-') {
  eval {
    while(<>) {
      print scalar(localtime), ' ', $_;
    }
  };
  exit(0);
}

1;
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and then from your script, just use the module, and then print whatever you want:

#!/usr/bin/perl

use MyApp::Logger;

print "foo\nbar\n";
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open( CMD, "mycmd arguments wubba |" ) or die "Can't open pipe from my
+cmd: $!\n";
while( <CMD> ) {
  print scalar localtime, ": ", $_;
}
close( CMD );
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If you need fancier you might want to look at IPC::Run or the like.

I call an ARSPerl function e.g. login, which only returns a structure, but opens its own stream to STDOUT. I have redirected STDOUT to a log file which i also write to using print statements in the format e.g.

Sun May 29 11:15:46 2005        Successfully generated query.
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but my redirect of STDOUT does not allow formatting. e.g. my line of perl code:

($control = ars_Login($arsserver, $arsuser, $arspass))
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produces this text, sent directly to STDOUT

[ARS.xs 201] XS_ARS_ars_Login : ars_Login(arsprod, hp_servicecall, [nu
+ll])
[ARS.xs 292] XS_ARS_ars_Login : finished.
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I want to enforce formatting rules so any print statement, even ones from the library call, have to obey i.e. including datetime.

Janitored by holli - fixed formatting

use IO::Scalar;
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my $output = scalar(localtime()).$system_call;
print $output,"\n";
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lupey

Im running a binary which returns text - without me being able to do any handling e.g. concatenating strings. I want to change the default formatting to include a timestamp.

You can capture the output from an executable file by using backticks ``. Then, you can do whatever you want to the output: add a prefix, a suffix, or change it completely with regular expressions. In the following code, I'm capturing the output of echo and prefixing the date. Replace echo with the binary of your choice.

use strict;
my $system_call = `echo hello world`;
my $output = scalar(localtime())." $system_call";
print STDOUT $output,"\n";

# output
# Tue May 31 09:04:22 2005 hello world
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If this isn't what you are looking for, please be more explicit in your posts.

lupey