CODEWITHSUNDEEP
perldebugging
HRitter
HRitter

Reputation: 301

Alias definition in .perldb (Perl Debugger) for expression evaluation 'x' doesn't work

I am wondering if there is a way to define aliases in the Perl Debugger configuration file .perldb for the command x which dumps expressions.

All the following imaginable varieties of alias definitions doesn't work:

cat .perldb
$DB::alias{ 'x0' }    = "x '%states'";             # Does not work
$DB::alias{ 'x1' }    = 'x %config';               # Does not work
$DB::alias{ 'x2' }    = '"x %config"';             # Does not work
$DB::alias{ 'x3' }    = 'x "%config, $foo"';       # Does not work
$DB::alias{ 'x4' }    = 'x "@L"';                  # Does not work
$DB::alias{ 'x5' }    = 'x %config, $foo';         # Does not work
$DB::alias{ 'x6' }    = '"x %config, $foo"';       # Does not work
$DB::alias{ 'xc' }    = 'x %config';               # Does not work
$DB::alias{ 'pFoo1' } = 'print("foo=$var1\n")';    # Works
$DB::alias{ 'pFoo2' } = 'print("$var2\n")';        # Works
$DB::alias{ 'p1' }    = 'print "\$_ =  $_"';       # Works
$DB::alias{ 'code' }  = 's/^.*$/l 1+99999/';       # Works

After starting the debugger with 'perl -d script.pl' and display the aliases with = I get:

code    s/^.*$/l 1+99999/
p1  print "\$_ =  $_"
pFoo1   print("foo=$var1\n")
pFoo2   print("$var2\n")
x0  x '%states'
x1  x %config
x2  "x %config"
x3  x "%config, $foo"
x4  x "@L"
x5  x %config, $foo
x6  "x %config, $foo"
xc  x %config

Any ideas if the alias definitions in .perldb expect a special syntax or does it just not work?

Upvotes: 3

Views: 112

Answers (1)

melpomene
melpomene

Reputation: 85837

This is not documented, but the contents of the %alias hash are strings that are used as the right-hand side of a $cmd =~ ... expression. That is, to work as expected, the aliases must be s/// commands.

Try something like

$DB::alias{ 'x1' } = 's/^.*/x %config/';

Upvotes: 3

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