perldiag
TLDR
View all Perl diagnostics
$ perldoc perldiag
Search for specific message$ perldoc perldiag | grep "[error message]"
Use splain for explanations$ perl [script.pl] 2>&1 | splain
Enable verbose warnings$ perl -Mdiagnostics [script.pl]
SYNOPSIS
perldoc perldiag
splain [errormessage_]
DESCRIPTION
perldiag is a Perl documentation file containing all diagnostic messages that Perl can produce. Each message includes explanation and suggested fixes.
Access via perldoc or use diagnostics module for runtime explanations.
EXAMPLES
$ # Read full diagnostics
perldoc perldiag
# Use diagnostics module in script
perl -Mdiagnostics script.pl
# Explain error messages
echo "Use of uninitialized value" | splain
perldoc perldiag
# Use diagnostics module in script
perl -Mdiagnostics script.pl
# Explain error messages
echo "Use of uninitialized value" | splain
IN SCRIPT
$ use diagnostics; # Verbose messages
use warnings; # Enable warnings
# Or for specific categories
use warnings qw(all);
no warnings qw(uninitialized);
use warnings; # Enable warnings
# Or for specific categories
use warnings qw(all);
no warnings qw(uninitialized);
MESSAGE TYPES
$ (W) Warning - may indicate problem
(D) Deprecation - feature being removed
(S) Severe warning - almost certainly wrong
(F) Fatal - compilation error
(X) Alien - error from external source
(D) Deprecation - feature being removed
(S) Severe warning - almost certainly wrong
(F) Fatal - compilation error
(X) Alien - error from external source
CAVEATS
Part of core Perl documentation. diagnostics module adds runtime overhead. Use only during development.
HISTORY
perldiag is part of Perl core documentation by Larry Wall and the Perl community.
