6.7. Ruby command line options

Ruby is typically run from the command line as follows:

$ ruby [ options ] [.] [ programfile ] [ arguments ... ]

The interpreter can be called through the following options to control the environment and behavior of the interpreter.

Option	Description
`-a`	When used with-n or-p, you can turn on automatic split mode (auto split mode). Check the-n and-p options.
`-c`	Only check the syntax, do not execute the program.
`-C dir`	Change the directory before execution (equivalent to-X).
`-d`	Enable debug mode (equivalent to-debug).
`-F pat`	Specify pat as the default detach mode ($;).
`-e prog`	Specifies that prog is executed on the command line as a program. You can specify multiple-e options to execute multiple programs.
`-h`	Displays an overview of command line options.
`-i [ ext]`	Rewrite the contents of the file as program output. The original file is saved with the extension ext. If no ext is specified, the original file is deleted.
`-I dir`	Add dir as the directory to load the library.
`-K [ kcode]`	Specifies the multibyte character set encoding. E or E corresponds to EUC (extended Unix code), s or S corresponds to SJIS (Shift-JIS), u or U corresponds to UTF-8,a, A, n or N corresponds to ASCII.
`-l`	Enable automatic line end processing. Remove a newline character from the input line and append a newline character to the output line.
`-n`	Place the code in an input loop (as in while gets;. Same in end).
`-0[ octal]`	Set the default record delimiter ($/) to octal. If octal is not specified, it defaults to0.
`-p`	Place the code in an input loop. Output variables after each iteration $_ The value of.
`-r lib`	Use require to load lib as a pre-execution library.
`-s`	Interpret the matching pattern between the program name and the file name parameter-any parameter of xxx as a switch and define the corresponding variable.
`-T [level]`	Set the security level and perform an impurity test (if level is not specified, the default is 1).
`-v`	Displays the version and enables redundancy mode.
`-w`	Enable redundancy mode. If no program file is specified, it is read from STDIN.
`-x [dir]`	Delete the text before the #! ruby line. If dir is specified, change the directory to dir.
`-X dir`	Change the directory before execution (equivalent to-C).
`-y`	Enable parser debug mode.
`--copyright`	Displays the copyright notice.
`--debug`	Enable debug mode (equivalent to-d).
`--help`	Displays an overview of command line options (equivalent to-h).
`--version`	Displays the version.
`--verbose`	Enable redundancy mode (equivalent to-v). Set $VERBOSE to true.
`--yydebug`	Enable 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