diff options
Diffstat (limited to 'Documentation/technical/api-parse-options.txt')
| -rw-r--r-- | Documentation/technical/api-parse-options.txt | 71 |
1 files changed, 49 insertions, 22 deletions
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 50f9e9ac17..3062389404 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -21,7 +21,7 @@ that allow to change the behavior of a command. * There are basically two forms of options: 'Short options' consist of one dash (`-`) and one alphanumeric character. - 'Long options' begin with two dashes (`\--`) and some + 'Long options' begin with two dashes (`--`) and some alphanumeric characters. * Options are case-sensitive. @@ -31,7 +31,7 @@ The parse-options API allows: * 'sticked' and 'separate form' of options with arguments. `-oArg` is sticked, `-o Arg` is separate form. - `\--option=Arg` is sticked, `\--option Arg` is separate form. + `--option=Arg` is sticked, `--option Arg` is separate form. * Long options may be 'abbreviated', as long as the abbreviation is unambiguous. @@ -39,11 +39,12 @@ The parse-options API allows: * Short options may be bundled, e.g. `-a -b` can be specified as `-ab`. * Boolean long options can be 'negated' (or 'unset') by prepending - `no-`, e.g. `\--no-abbrev` instead of `\--abbrev`. + `no-`, e.g. `--no-abbrev` instead of `--abbrev`. Conversely, + options that begin with `no-` can be 'negated' by removing it. -* Options and non-option arguments can clearly be separated using the `\--` - option, e.g. `-a -b \--option \-- \--this-is-a-file` indicates that - `\--this-is-a-file` must not be processed as an option. +* Options and non-option arguments can clearly be separated using the `--` + option, e.g. `-a -b --option -- --this-is-a-file` indicates that + `--this-is-a-file` must not be processed as an option. Steps to parse options ---------------------- @@ -75,7 +76,7 @@ before the full parser, which in turn shows the full help message. Flags are the bitwise-or of: `PARSE_OPT_KEEP_DASHDASH`:: - Keep the `\--` that usually separates options from + Keep the `--` that usually separates options from non-option arguments. `PARSE_OPT_STOP_AT_NON_OPTION`:: @@ -113,25 +114,36 @@ say `static struct option builtin_add_options[]`. There are some macros to easily define options: `OPT__ABBREV(&int_var)`:: - Add `\--abbrev[=<n>]`. + Add `--abbrev[=<n>]`. -`OPT__DRY_RUN(&int_var)`:: - Add `-n, \--dry-run`. +`OPT__COLOR(&int_var, description)`:: + Add `--color[=<when>]` and `--no-color`. -`OPT__QUIET(&int_var)`:: - Add `-q, \--quiet`. +`OPT__DRY_RUN(&int_var, description)`:: + Add `-n, --dry-run`. -`OPT__VERBOSE(&int_var)`:: - Add `-v, \--verbose`. +`OPT__FORCE(&int_var, description)`:: + Add `-f, --force`. + +`OPT__QUIET(&int_var, description)`:: + Add `-q, --quiet`. + +`OPT__VERBOSE(&int_var, description)`:: + Add `-v, --verbose`. `OPT_GROUP(description)`:: Start an option group. `description` is a short string that describes the group or an empty string. Start the description with an upper-case letter. -`OPT_BOOLEAN(short, long, &int_var, description)`:: - Introduce a boolean option. - `int_var` is incremented on each use. +`OPT_BOOL(short, long, &int_var, description)`:: + Introduce a boolean option. `int_var` is set to one with + `--option` and set to zero with `--no-option`. + +`OPT_COUNTUP(short, long, &int_var, description)`:: + Introduce a count-up option. + `int_var` is incremented on each use of `--option`, and + reset to zero with `--no-option`. `OPT_BIT(short, long, &int_var, description, mask)`:: Introduce a boolean option. @@ -142,8 +154,9 @@ There are some macros to easily define options: If used, `int_var` is bitwise-anded with the inverted `mask`. `OPT_SET_INT(short, long, &int_var, description, integer)`:: - Introduce a boolean option. - If used, set `int_var` to `integer`. + Introduce an integer option. + `int_var` is set to `integer` with `--option`, and + reset to zero with `--no-option`. `OPT_SET_PTR(short, long, &ptr_var, description, ptr)`:: Introduce a boolean option. @@ -183,16 +196,30 @@ There are some macros to easily define options: arguments. Short options that happen to be digits take precedence over it. +`OPT_COLOR_FLAG(short, long, &int_var, description)`:: + Introduce an option that takes an optional argument that can + have one of three values: "always", "never", or "auto". If the + argument is not given, it defaults to "always". The `--no-` form + works like `--long=never`; it cannot take an argument. If + "always", set `int_var` to 1; if "never", set `int_var` to 0; if + "auto", set `int_var` to 1 if stdout is a tty or a pager, + 0 otherwise. + +`OPT_NOOP_NOARG(short, long)`:: + Introduce an option that has no effect and takes no arguments. + Use it to hide deprecated options that are still to be recognized + and ignored silently. + The last element of the array must be `OPT_END()`. If not stated otherwise, interpret the arguments as follows: * `short` is a character for the short option - (e.g. `\'e\'` for `-e`, use `0` to omit), + (e.g. `'e'` for `-e`, use `0` to omit), * `long` is a string for the long option - (e.g. `"example"` for `\--example`, use `NULL` to omit), + (e.g. `"example"` for `--example`, use `NULL` to omit), * `int_var` is an integer variable, @@ -217,7 +244,7 @@ The callback mechanism is as follows: * Inside `func`, the only interesting member of the structure given by `opt` is the void pointer `opt->value`. - `\*opt->value` will be the value that is saved into `var`, if you + `*opt->value` will be the value that is saved into `var`, if you use `OPT_CALLBACK()`. For example, do `*(unsigned long *)opt->value = 42;` to get 42 into an `unsigned long` variable. |