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# End of Options

The options of UNIX® utilities usually are introduced with a dash (`-`) character.

This is problematic when a non-option argument has to be specified that begins with a dash. A common example for this are filenames.

Many utilities use the convention to specify two consecutive dashes (`--`) to signal \"end of options at this point\". Beyond this tag, no options are processed anymore, even if an argument begins with a dash.

Example: You want to list (`ls`) the file with the name `-hello`. With common option processing, this could end up in the ls-options `-h`, `-e`, `-l` and `-o` and probably in an error message about invalid options. You use this to avoid the wrong option processing:

    ls -- -hello

POSIX® specifies that every utility should follow this rule (see ch. 12.2 Utility Syntax Guidelines), except

- `echo` (historical reasons)
- `test` (obvious parsing reasons)

## See also

- Scripting article, internal: getopts_tutorial

November 7, 2024
November 7, 2024

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