Ruby Command Line Options
Ruby is generally run from the command line as follows:
$ ruby [ options ] [.] [ programfile ] [ arguments ... ]
The interpreter can be invoked with the following options to control the interpreter's environment and behavior.
| Option | Description |
|---|---|
| -a | When used with -n or -p, enables auto split mode. See the -n and -p options. |
| -c | Checks syntax only, without executing the program. |
| -C dir | Changes directory before execution (equivalent to -X). |
| -d | Enables debug mode (equivalent to -debug). |
| -F pat | Specifies pat as the default split pattern ($;). |
| -e prog | Specifies prog as the program to execute from the command line. Multiple -e options can be specified to execute multiple programs. |
| -h | Displays an overview of command line options. |
| -i [ ext] | Rewrites file contents as program output. The original file is saved with extension ext. If ext is not specified, the original file is deleted. |
| -I dir | Adds dir as a directory for loading libraries. |
| -K [ kcode] | Specifies multibyte character set encoding. e or E corresponds to EUC (extended Unix code), s or S corresponds to SJIS (Shift-JIS), u or U corresponds to UTF-8, a, A, n or N corresponds to ASCII. |
| -l | Enables automatic line ending processing. Removes a newline from input lines and appends a newline to output lines. |
| -n | Places the code in an input loop (like in while gets; ... end). |
| -0[ octal] | Sets the default record separator ($/) to octal. If octal is not specified, it defaults to \0. |
| -p | Places the code in an input loop. Outputs the value of variable $_ after each iteration. |
| -r lib | Userequireto loadlibas a library before execution. |
| -s | Interprets any argument matching the -xxx pattern between the program name and filename arguments as a switch, and defines the corresponding variable. |
| -T [level] | Sets the safety level, performing taint check (if level is not specified, the default value is 1). |
| -v | Displays version and enables verbose mode. |
| -w | Enables verbose mode. If no program file is specified, reads from STDIN. |
| -x [dir] | Deletes text before the #!ruby line. If specifieddir, changes the directory todir。 |
| -X dir | Changes directory before execution (equivalent to -C). |
| -y | Enables parser debug mode. |
| --copyright | Displays copyright notice. |
| --debug | Enables debug mode (equivalent to -d). |
| --help | Displays an overview of command line options (equivalent to -h). |
| --version | Displays version. |
| --verbose | Enables verbose mode (equivalent to -v). Sets $VERBOSE to true. |
| --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/binOther Extensions