Perl Pocket Reference, 4th Edition

Chapter 42. The Perl Debugger

The Perl symbolic debugger is invoked with perl -d.

Any input to the debugger that is not one of the commands enumerated below is evaluated as a Perl expression.

a [ line ] command

Sets an action for line.

A [ line ]

Deletes the action at the given line; default is the current line. If line is *, deletes all line actions.

b [ line [ condition ] ]

Sets a breakpoint at line; default is the current line.

b subname [ condition ]

Sets a breakpoint at the named subroutine.

b compile subname

Stops after the subroutine is compiled.

b load file

Sets a breakpoint at requireing the given file.

b postpone subname [ condition ]

Sets a breakpoint at the first line of the subroutine after it is compiled.

B [ line ]

Deletes the breakpoint at the given line; default is the current line. If line is *, deletes all breakpoints.

c [ line ]

Continues (until line, or another breakpoint, or exit).

f file

Switches to file and starts listing it.

h

Prints out a long help message.

h cmd

Prints out help for debugger command cmd.

h h

Prints out a concise help message.

H [ -number ]

Displays the last -number commands.

l [ range ]

Lists a range of lines. range may be a number, start - end, start + amount, or a subroutine name. If range is omitted, lists the next screenful.

l subname

Lists the named subroutine.

L [ a|b|w ]

Lists lines with actions, breakpoints, or watches.

m class

Prints the methods callable via the given class.

m expr

Evaluates the expression in list context, prints the methods callable on the first element ...