getopts(1) -- Parse CLI options =============================== ## SYNOPSIS `getopts` [*options* ...]
`getopts` [*options* ...] `|` `while` read -l key value; ...; `end`
## DESCRIPTION getopts is a command line parser, designed to process command line arguments based in the POSIX Utility Syntax Guidelines. If no arguments are given getopts returns `1`. ## USAGE In the following example: ``` getopts -ab1 --foo=bar baz ``` And its output: ``` a b 1 foo bar _ baz ``` The items on the left represent the option flags or *keys* associated with the CLI. The items on the right are the option *values*. The underscore `_` character is the default *key* for arguments without a key. Use `read(1)` to process the generated stream and `switch(1)` to match patterns: ``` getopts -ab1 --foo=bar baz | while read -l key option switch $key case _ case a case b case foo end end ``` ## OPTIONS None. ## EXAMPLES The following is a mock of `fish(1)` CLI missing the implementation: ``` function fish set -l mode set -l flags set -l commands set -l debug_level getopts $argv | while read -l key value switch $key case c command set commands $commands $value case d debug-level set debug_level $value case i interactive set mode $value case l login set mode $value case n no-execute set mode $value case p profile set flags $flags $value case h help printf "usage: $_ [OPTIONS] [-c command] [FILE [ARGUMENTS...]]\n" return case \* printf "$_: '%s' is not a valid option.\n" $key return 1 end end # Implementation end ``` ## BUGS * getopts does *not* read the standard input. Use getopts to collect options and the standard input to process a stream of data relevant to your program. * A double dash, `--`, marks the end of options. Arguments after this sequence are placed in the default underscore key, `_`. * The getopts described in this document is *not* equivalent to the getopts *builtin* found in other shells. ## AUTHORS Jorge Bucaran . ## SEE ALSO POSIX Utility Syntax Guidelines [goo.gl/yrgQn9]