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Perl builtin functions
A list of Perl builtin functions. Builtin functions are functions that Perl provides from the beginning. Explains how to call a function, pass arguments, and receive a return value. Please use it as a reference.
String
A function used to process strings.
| join | Concatenate strings by specifying a delimiter |
| length | Get the length of a string |
| substr | Cut and replace strings |
| index | Character search |
| rindex | Search for characters (from the end) |
| split | Split a string by specifying a delimiter |
| reverse | Reverse the strings |
| uc | Convert to uppercase |
| ucfirst | Convert first letter to uppercase |
| lc | Convert to lowercase |
| lcfirst | Convert first letter to lowercase |
| sprintf | Format string |
| chomp | Remove a line break |
| chr | Convert numbers to ASCII characters |
| ord | Convert ASCII characters to numbers |
| oct | Octal conversion |
| hex | Hexadecimal conversion |
| crypt | Create a digest and check your password |
Regular expression
Functions related to regular expression.
| quotemeta | Regular expression escape |
Array manipulation
A function for manipulating arrays.
| shift | Extract the beginning of an array element |
| unshift | Add element to the beginning of the array |
| pop | Extract the last element of the array |
| push | Add elements to the end of the array |
| splice | Detailed manipulation of array elements |
| grep | Extract elements that match the conditions |
| map | Map values |
| sort | sort |
| reverse | Reverse the order of the array |
Hash operation
A function for manipulating hashes.
| keys | Get a list of hash keys |
| values | Get a list of hash values |
| each | Fetch the hash key and value in order |
| exists | Confirmation of the existence of the hash key |
| delete | Delete hash key and value |
| reverse | Swap the hash key and value |
Subroutine
Functions related to subroutine.
| wantarray | Judgment of context |
| caller | Caller information |
| return | Returns a return value |
File input/output
Function used for file input/output.
| String output | |
| printf | Formatted string output |
| open | File open |
| close | File close |
| sysopen | Low level file open |
| getc | Get one character |
| binmode | Open mode change |
| flock | File lock |
| opendir | Directory open |
| closeddir | Directory closed |
| readdir | Read directory |
| read | Read from a file by specifying the number of bytes |
| sysread | Read from a file with a specified number of bytes (no buffering) |
| syswrite | Write to file by specifying the number of bytes (no buffering) |
Value definition
A function related to the definition of a value.
| undef | Get and set undefined values |
| defined | Check if the value is defined |
Context
| scalar function | Evaluate in scalar context |
File operation
Create/delete files/directories and other functions.
| unlink | Delete file |
| chdir | Change current directory |
| mkdir | Creating a directory |
| rmdir | Delete directory |
| chmod | Change permissions |
| stat | Get file information |
| fileno | Get file descriptor |
| glob | Get a list of files |
| umask | Mask settings |
| __LINE__ | Get line number |
| __FILE__ | Get file name |
| __DATA__ | Data section |
Date/Time
A function that manipulates date/time.
| time | Current time |
| localtime | Current time(with locale) |
| sleep | Sleep for a specified time |
Mathematical functions
Mathematical function.
| abs | Absolute value |
| sqrt | square root |
| int | Get the integer part |
| ceil | Round up the decimal point |
| floor | Decimal point devaluation |
| rand | Random value |
| looks_like_number | Numerical judgment |
| pi | pie |
| deg2rad | Angle conversion |
| sin | Ask for a sign |
| cos | Ask for cosine |
| exp | Exponential |
| log | Log function |
| srand | Reproducible random numbers |
See the following articles for the basics of handling numbers in Perl.
Object Oriented
Functions related to object-oriented.
| bless | Object creation |
| __PACKAGE__ | Get the package name |
Exception handling
Function used in Exception handling.
| die | Exit the program |
| warn | Output warning |
| eval | Catch the exception |
Interprocess communication
Function used in interprocess communication.
| system | Run another process |
| fork | Fork |
| wait | Wait for child process |
| getpwuid | Get user ID |
| getpwnam | Get username |
| getgrnam | Get group name |
| kill | Kill the process |
Read configuration file
| do | Read the configuration file |
Binary processing
| pack | Pack the data in binary format |
| unpack | Restore packed data |
FAQ
Where are the syntaxes such as if, for, and foreach explained?
For syntax such as if, for, and foreach, see the article on the syntax list.
How do I create my own function?
If you want to create the function yourself, see the following article. We use a function called a subroutine.