# Check syntax
perl -c script.pl

# With warnings
perl -wc script.pl

# Check module
perl -c -I lib lib/MyApp/Module.pm

script.pl syntax OK

syntax error at script.pl line 15, near "my $"
script.pl had compilation errors.

#!/usr/bin/env perl
use strict;
use warnings;
use autodie;  # For scripts with file operations

# Check for strict
grep -l 'use strict' script.pl || echo "MISSING: use strict"

# Check for warnings
grep -l 'use warnings' script.pl || echo "MISSING: use warnings"

# Check shebang
head -1 script.pl | grep -q '^#!' || echo "MISSING: shebang line"

# Find two-argument open
grep -n 'open\s\+[A-Z]\+\s*,' script.pl

# Find unsafe backticks
grep -n '`.*\$' script.pl

# Find string eval
grep -n 'eval\s*"' script.pl

# Check for system with string
grep -n 'system\s*"' script.pl

# Find undeclared variables (after perl -c passes)
# These would be caught by strict, but double-check:
grep -n '\$[a-z_][a-z0-9_]*\s*=' script.pl | head -20

# Good pattern
sub function_name {
    my ($arg1, $arg2) = @_;
    # ...
}

# Check for named parameters
grep -n 'sub.*{' script.pl

# Find eval blocks without error check
grep -n 'eval\s*{' script.pl

# These should be followed by or do { } patterns

# Validate POD syntax
podchecker script.pl

# Check for POD presence
perl -MPod::Usage -e 'pod2usage(-input => shift)' script.pl >/dev/null 2>&1 || echo "No POD documentation"

# Check for NAME section
grep -l '^=head1 NAME' script.pl || echo "MISSING: =head1 NAME"

# Check for SYNOPSIS
grep -l '^=head1 SYNOPSIS' script.pl || echo "MISSING: =head1 SYNOPSIS"

perl -wc script.pl

head -10 script.pl | grep -E 'use (strict|warnings|autodie)'

perlcritic --severity 5 script.pl

perl -wc script.pl && \
  grep -q 'use strict' script.pl && \
  grep -q 'use warnings' script.pl && \
  echo "Basic validation passed"

use strict;
use warnings;

# Wrong
open FILE, $filename;

# Correct
open my $fh, '<', $filename;

# Wrong
system("rm $file");
`ls $dir`;

# Correct
use IPC::System::Simple qw(system capture);
system('rm', $file);
my $output = capture('ls', $dir);

# Wrong
open my $fh, '<', $file;

# Correct (with autodie)
use autodie;
open my $fh, '<', $file;

# Or explicit
open my $fh, '<', $file
    or die "Cannot open $file: $!";