NAME

ebug - A simple, extensible console Perl debugger

VERSION

version 0.67

SYNOPSIS

% ebug calc.pl
% ebug add.pl 3 "four and a half"
% ebug "add.pl 3 4"

DESCRIPTION

ebug is an interactive command-line front end to Devel::ebug. It is a simple Perl debugger, much like perl5db.pl.

Any arguments after the program name are passed to the program, each exactly as given, so an argument may contain spaces or other shell metacharacters. If the program and its arguments are given together as a single string instead, that string is interpreted by the shell.

COMMANDS

At the ebug: prompt, type one of the following commands and press return. Pressing return with an empty line repeats the last command (handy for repeatedly pressing s or n to step through code). Anything that isn't recognized as a command below is evaluated as Perl code in the debuggee, the same as the e command.

? or h

Show this list of commands.

b LINE

b LINE CONDITION

Set a break point at LINE in the current file, optionally only breaking when CONDITION is true (eg: b 6, b 6 $x > 7).

b FILE LINE

b FILE LINE CONDITION

Set a break point at LINE in FILE (eg: b code.pl 6).

b SUBROUTINE

b SUBROUTINE CONDITION

Set a break point at the start of SUBROUTINE, given as a fully qualified name, optionally only breaking when CONDITION is true. The condition is checked as the subroutine is entered, so @_ holds its arguments (eg: b Calc::fib, b Calc::fib $_[1] > 5).

bf FILE

Set a break point that triggers as soon as FILE is loaded (eg: bf Calc.pm).

d LINE

d FILE LINE

Delete the break point at LINE in the current file, or in FILE.

e EXPR

Evaluate EXPR as Perl code in the debuggee and print the result (eg: e $x+$y).

f

Show all the filenames currently loaded.

l

List code lines around the current line.

l N

List code lines around the current line, and remember N as the number of lines to show from now on.

L

Toggle always listing code lines before each prompt.

n

Next: step onto the next line, stepping over any subroutine calls.

o

Show the debuggee's captured STDOUT and STDERR.

p

Show the pad: all lexical (my) variables in scope.

r

Run until the next break point or watch point. Pressing Ctrl-C (SIGINT) while running stops the debuggee and drops back into the ebug: prompt instead of killing the console.

ret

ret VALUE

Return from the current subroutine, optionally forcing the return value to VALUE for testing purposes (eg: ret 3.141).

restart

Restart the program from the beginning.

s

Step: step onto the next line, stepping into any subroutine calls.

T

Show a stack trace.

u

u N

Undo the last command, or the last N commands. This restarts the debuggee and replays the previous session's state-changing commands.

w CONDITION

Set a watch point: execution stops as soon as CONDITION becomes true (eg: w $t > 10).

x EXPR

Evaluate EXPR and dump the result using YAML (eg: x $object). Pressing Tab after x completes on the names of variables currently in the pad.

q

Quit ebug.

SEE ALSO

Devel::ebug

AUTHOR

Original author: Leon Brocard <acme@astray.com>

Current maintainer: Graham Ollis <plicease@cpan.org>

Contributors:

Brock Wilcox <awwaiid@thelackthereof.org>

Taisuke Yamada

COPYRIGHT AND LICENSE

This software is copyright (c) 2005-2026 by Leon Brocard.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.