bash-hackers-wiki/docs/dict/end_of_options.md

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2023-07-05 11:06:16 +02:00
# End of Options
The options of UNIX(r) 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(r) specifies that every utility should follow this rule (see ch.
[12.2 Utility Syntax
Guidelines](https://pubs.opengroup.org/onlinepubs/9699919799.2013edition/basedefs/V1_chap12.html)),
except
- `echo` (historical reasons)
- `test` (obvious parsing reasons)
## See also
- Scripting article, internal:
[getopts_tutorial](../howto/getopts_tutorial.md)