- Ruby Basics
- Ruby - Home
- Ruby - Overview
- Ruby - Environment Setup
- Ruby - Syntax
- Ruby - Classes and Objects
- Ruby - Variables
- Ruby - Operators
- Ruby - Comments
- Ruby - IF...ELSE
- Ruby - Loops
- Ruby - Methods
- Ruby - Blocks
- Ruby - Modules
- Ruby - Strings
- Ruby - Arrays
- Ruby - Hashes
- Ruby - Date & Time
- Ruby - Ranges
- Ruby - Iterators
- Ruby - File I/O
- Ruby - Exceptions
- Ruby Advanced
- Ruby - Object Oriented
- Ruby - Regular Expressions
- Ruby - Database Access
- Ruby - Web Applications
- Ruby - Sending Email
- Ruby - Socket Programming
- Ruby - Ruby/XML, XSLT
- Ruby - Web Services
- Ruby - Tk Guide
- Ruby - Ruby/LDAP Tutorial
- Ruby - Multithreading
- Ruby - Built-in Functions
- Ruby - Predefined Variables
- Ruby - Predefined Constants
- Ruby - Associated Tools
- Ruby Useful Resources
- Ruby - Quick Guide
- Ruby - Useful Resources
- Ruby - Discussion
- Ruby - Ruby on Rails Tutorial
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Ruby - Command Line Options
Ruby is generally run from the command line in the following way −
$ ruby [ options ] [.] [ programfile ] [ arguments ... ]
The interpreter can be invoked with any of the following options to control the environment and behavior of the interpreter.
| Sr.No. | Option & Description |
|---|---|
| 1 | -a Used with -n or -p to split each line. Check -n and -p options. |
| 2 | -c Checks syntax only, without executing program. |
| 3 | -C dir Changes directory before executing (equivalent to -X). |
| 4 | -d Enables debug mode (equivalent to -debug). |
| 5 | -F pat Specifies pat as the default separator pattern ($;) used by split. |
| 6 | -e prog Specifies prog as the program from the command line. Specify multiple -e options for multiline programs. |
| 7 | -h Displays an overview of command-line options. |
| 8 | -i [ ext] Overwrites the file contents with program output. The original file is saved with the extension ext. If ext isn't specified, the original file is deleted. |
| 9 | -I dir Adds dir as the directory for loading libraries. |
| 10 | -K [ kcode] Specifies the multibyte character set code (e or E for EUC (extended Unix code); s or S for SJIS (Shift-JIS); u or U for UTF8; and a, A, n, or N for ASCII). |
| 11 | -l Enables automatic line-end processing. Chops a newline from input lines and appends a newline to output lines. |
| 12 | -n Places code within an input loop (as in while gets; ... end). |
| 13 | -0[ octal] Sets default record separator ($/) as an octal. Defaults to \0 if octal not specified. |
| 14 | -p Places code within an input loop. Writes $_ for each iteration. |
| 15 | -r lib Uses require to load lib as a library before executing. |
| 16 | -s Interprets any arguments between the program name and filename arguments fitting the pattern -xxx as a switch and defines the corresponding variable. |
| 17 | -T [level] Sets the level for tainting checks (1 if level not specified). |
| 18 | -v Displays version and enables verbose mode. |
| 19 | -w Enables verbose mode. If program file not specified, reads from STDIN. |
| 20 | -x [dir] Strips text before #!ruby line. Changes directory to dir before executing if dir is specified. |
| 21 | -X dir Changes directory before executing (equivalent to -C). |
| 22 | -y Enables parser debug mode. |
| 23 | --copyright Displays copyright notice. |
| 24 | --debug Enables debug mode (equivalent to -d). |
| 25 | --help Displays an overview of command-line options (equivalent to h). |
| 26 | --version Displays version. |
| 27 | --verbose Enables verbose mode (equivalent to -v). Sets $VERBOSE to true. |
| 28 | --yydebug Enables parser debug mode (equivalent to -y). |
Single character command-line options can be combined. The following two lines express the same meaning −
$ruby -ne 'print if /Ruby/' /usr/share/bin $ruby -n -e 'print if /Ruby/' /usr/share/bin