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Trace(3)	      User Contributed Perl Documentation	      Trace(3)

NAME
       Devel::Trace - Print out	each line before it is executed	(like "sh -x")

SYNOPSIS
	 perl -d:Trace program

DESCRIPTION
       If you run your program with "perl -d:Trace program", this module will
       print a message to standard error just before each line is executed.
       For example, if your program looks like this:

	       #!/usr/bin/perl

	       print "Statement	1 at line 4\n";
	       print "Statement	2 at line 5\n";
	       print "Call to sub x returns ", &x(), " at line 6.\n";

	       exit 0;

	       sub x {
		 print "In sub x at line 12.\n";
		 return	13;
	       }

       Then  the "Trace" output	will look like this:

	       >> ./test:4: print "Statement 1 at line 4\n";
	       >> ./test:5: print "Statement 2 at line 5\n";
	       >> ./test:6: print "Call	to sub x returns ", &x(), " at line 6.\n";
	       >> ./test:12:   print "In sub x at line 12.\n";
	       >> ./test:13:   return 13;
	       >> ./test:8: exit 0;

       This is something like the shell's "-x" option.

DETAILS
       Inside your program, you	can enable and disable tracing by doing

	   $Devel::Trace::TRACE	= 1;   # Enable
	   $Devel::Trace::TRACE	= 0;   # Disable

       or

	   Devel::Trace::trace('on');  # Enable
	   Devel::Trace::trace('off'); # Disable

       "Devel::Trace" exports the "trace" function if you ask it to:

	   import Devel::Trace 'trace';

       Then if you want	you just say

	   trace 'on';		       # Enable
	   trace 'off';		       # Disable

TODO
       o   You should be able to  send the trace output	to the filehandle of
	   your	choice.

       o   You should be able to specify the format of the output.

       o   You should be able to get the output	into a string.

       We'll see.

LICENSE
       Devel::Trace 0.11 and its source	code are hereby	placed in the public
       domain.

Author
       Mark-Jason Dominus (C<mjd-perl-trace@plover.com>), Plover Systems co.
       See the C<Devel::Trace.pm> Page at
       http://www.plover.com/~mjd/perl/Trace for news and upgrades.

perl v5.24.1			  2012-02-16			      Trace(3)

NAME | SYNOPSIS | DESCRIPTION | DETAILS | TODO | LICENSE | Author

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=Devel::Trace&sektion=3&manpath=FreeBSD+12.1-RELEASE+and+Ports>

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