281 lines
3.6 KiB
Markdown
281 lines
3.6 KiB
Markdown
# Perl Cheat Sheet
|
|
|
|
## Basics
|
|
|
|
### Comments
|
|
```perl
|
|
# This is a comment
|
|
```
|
|
|
|
### Print
|
|
```perl
|
|
print "Hello, World!\n";
|
|
```
|
|
|
|
### Variables
|
|
```perl
|
|
$scalar_variable = 42;
|
|
@array_variable = (1, 2, 3);
|
|
%hash_variable = ('key' => 'value');
|
|
```
|
|
|
|
## Control Structures
|
|
|
|
### if-else
|
|
```perl
|
|
if ($condition) {
|
|
# Code to execute if condition is true
|
|
} else {
|
|
# Code to execute if condition is false
|
|
}
|
|
```
|
|
|
|
### foreach
|
|
```perl
|
|
foreach $item (@array) {
|
|
# Code to execute for each item in the array
|
|
}
|
|
```
|
|
|
|
### while
|
|
```perl
|
|
while ($condition) {
|
|
# Code to execute while condition is true
|
|
}
|
|
```
|
|
|
|
## Subroutines
|
|
|
|
```perl
|
|
sub greet {
|
|
my $name = shift;
|
|
print "Hello, $name!\n";
|
|
}
|
|
|
|
greet("Alice");
|
|
```
|
|
|
|
## Regular Expressions
|
|
|
|
### Matching
|
|
```perl
|
|
if ($string =~ /pattern/) {
|
|
# Code to execute if pattern is found in $string
|
|
}
|
|
```
|
|
|
|
### Substitution
|
|
```perl
|
|
$string =~ s/find/replace/;
|
|
```
|
|
|
|
## File Handling
|
|
|
|
### Open and Read
|
|
```perl
|
|
open(my $file, '<', 'filename.txt') or die "Can't open file: $!";
|
|
while (<$file>) {
|
|
chomp;
|
|
print "$_\n";
|
|
}
|
|
close($file);
|
|
```
|
|
|
|
### Open and Write
|
|
```perl
|
|
open(my $file, '>', 'output.txt') or die "Can't open file: $!";
|
|
print $file "Hello, File!\n";
|
|
close($file);
|
|
```
|
|
|
|
## Modules
|
|
|
|
### Using Modules
|
|
```perl
|
|
use Module::Name;
|
|
```
|
|
|
|
### Exporting Functions
|
|
```perl
|
|
use Module::Name qw(function1 function2);
|
|
```
|
|
|
|
## References
|
|
|
|
### Scalar Reference
|
|
```perl
|
|
$scalar_ref = \$scalar_variable;
|
|
```
|
|
|
|
### Array Reference
|
|
```perl
|
|
$array_ref = \@array_variable;
|
|
```
|
|
|
|
### Hash Reference
|
|
```perl
|
|
$hash_ref = \%hash_variable;
|
|
```
|
|
|
|
# Advanced Perl Cheat Sheet
|
|
|
|
## Basics
|
|
|
|
### Comments
|
|
```perl
|
|
# This is a comment
|
|
```
|
|
|
|
### Print
|
|
```perl
|
|
print "Hello, World!\n";
|
|
```
|
|
|
|
### Variables
|
|
```perl
|
|
$scalar_variable = 42;
|
|
@array_variable = (1, 2, 3);
|
|
%hash_variable = ('key' => 'value');
|
|
```
|
|
|
|
### Data Types
|
|
```perl
|
|
$string = "Perl";
|
|
$number = 42;
|
|
$float = 3.14;
|
|
```
|
|
|
|
## Control Structures
|
|
|
|
### if-else
|
|
```perl
|
|
if ($condition) {
|
|
# Code to execute if condition is true
|
|
} elsif ($another_condition) {
|
|
# Code to execute if another condition is true
|
|
} else {
|
|
# Code to execute if all conditions are false
|
|
}
|
|
```
|
|
|
|
### foreach
|
|
```perl
|
|
foreach $item (@array) {
|
|
# Code to execute for each item in the array
|
|
}
|
|
```
|
|
|
|
### while
|
|
```perl
|
|
while ($condition) {
|
|
# Code to execute while condition is true
|
|
}
|
|
```
|
|
|
|
## Subroutines
|
|
|
|
```perl
|
|
sub greet {
|
|
my $name = shift;
|
|
print "Hello, $name!\n";
|
|
}
|
|
|
|
greet("Alice");
|
|
```
|
|
|
|
### Returning Values
|
|
```perl
|
|
sub add {
|
|
my ($num1, $num2) = @_;
|
|
return $num1 + $num2;
|
|
}
|
|
|
|
my $result = add(3, 4);
|
|
print "Sum: $result\n";
|
|
```
|
|
|
|
## Regular Expressions
|
|
|
|
### Matching
|
|
```perl
|
|
if ($string =~ /pattern/) {
|
|
# Code to execute if pattern is found in $string
|
|
}
|
|
```
|
|
|
|
### Substitution
|
|
```perl
|
|
$string =~ s/find/replace/;
|
|
```
|
|
|
|
## File Handling
|
|
|
|
### Open and Read
|
|
```perl
|
|
open(my $file, '<', 'filename.txt') or die "Can't open file: $!";
|
|
while (<$file>) {
|
|
chomp;
|
|
print "$_\n";
|
|
}
|
|
close($file);
|
|
```
|
|
|
|
### Open and Write
|
|
```perl
|
|
open(my $file, '>', 'output.txt') or die "Can't open file: $!";
|
|
print $file "Hello, File!\n";
|
|
close($file);
|
|
```
|
|
|
|
## Modules
|
|
|
|
### Using Modules
|
|
```perl
|
|
use Module::Name;
|
|
```
|
|
|
|
### Exporting Functions
|
|
```perl
|
|
use Module::Name qw(function1 function2);
|
|
```
|
|
|
|
## References
|
|
|
|
### Scalar Reference
|
|
```perl
|
|
$scalar_ref = \$scalar_variable;
|
|
```
|
|
|
|
### Array Reference
|
|
```perl
|
|
$array_ref = \@array_variable;
|
|
```
|
|
|
|
### Hash Reference
|
|
```perl
|
|
$hash_ref = \%hash_variable;
|
|
```
|
|
|
|
## Structuring a Perl Script for Bash
|
|
|
|
### Create a Perl Script
|
|
```perl
|
|
#!/usr/bin/perl
|
|
use strict;
|
|
use warnings;
|
|
|
|
# Perl script code here
|
|
print "Hello from Perl!\n";
|
|
```
|
|
|
|
### Make it Executable
|
|
```bash
|
|
chmod +x script.pl
|
|
```
|
|
|
|
### Run from Bash
|
|
```bash
|
|
./script.pl
|
|
```
|
|
|