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Diffstat (limited to 'Doc/help/getopts')
| -rw-r--r-- | Doc/help/getopts | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/Doc/help/getopts b/Doc/help/getopts new file mode 100644 index 000000000..bb89d2f2a --- /dev/null +++ b/Doc/help/getopts @@ -0,0 +1,31 @@ +getopts optstring name [ arg ... ] + Checks the args for legal options. If the args are omitted, use + the positional parameters. A valid option argument begins with + a `+' or a `-'. An argument not beginning with a `+' or a `-', + or the argument `--', ends the options. Note that a single `-' + is not considered a valid option argument. optstring contains + the letters that getopts recognizes. If a letter is followed by + a `:', that option requires an argument. The options can be + separated from the argument by blanks. + + Each time it is invoked, getopts places the option letter it + finds in the shell parameter name, prepended with a `+' when arg + begins with a `+'. The index of the next arg is stored in + OPTIND. The option argument, if any, is stored in OPTARG. + + The first option to be examined may be changed by explicitly as- + signing to OPTIND. OPTIND has an initial value of 1, and is + normally set to 1 upon entry to a shell function and restored + upon exit. (The POSIX_BUILTINS option disables this, and also + changes the way the value is calculated to match other shells.) + OPTARG is not reset and retains its value from the most recent + call to getopts. If either of OPTIND or OPTARG is explicitly + unset, it remains unset, and the index or option argument is not + stored. The option itself is still stored in name in this case. + + A leading `:' in optstring causes getopts to store the letter of + any invalid option in OPTARG, and to set name to `?' for an un- + known option and to `:' when a required argument is missing. + Otherwise, getopts sets name to `?' and prints an error message + when an option is invalid. The exit status is nonzero when + there are no more options. |