parse-options API
=================
-The parse-options API is used to parse and massage options in git
+The parse-options API is used to parse and massage options in Git
and to provide a usage help with consistent look.
Basics
* 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.
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.
+* 'stuck' and 'separate form' of options with arguments.
+ `-oArg` is stuck, `-o Arg` is separate form.
+ `--option=Arg` is stuck, `--option Arg` is separate form.
* Long options may be 'abbreviated', as long as the abbreviation
is unambiguous.
* 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`. Conversely,
+ `no-`, e.g. `--no-abbrev` instead of `--abbrev`. Conversely,
options that begin with `no-` can be 'negated' by removing it.
+ Other long options can be unset (e.g., set string to NULL, set
+ integer to 0) by prepending `no-`.
-* 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
----------------------
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`::
There are some macros to easily define options:
`OPT__ABBREV(&int_var)`::
- Add `\--abbrev[=<n>]`.
+ Add `--abbrev[=<n>]`.
`OPT__COLOR(&int_var, description)`::
- Add `\--color[=<when>]` and `--no-color`.
+ Add `--color[=<when>]` and `--no-color`.
`OPT__DRY_RUN(&int_var, description)`::
- Add `-n, \--dry-run`.
+ Add `-n, --dry-run`.
`OPT__FORCE(&int_var, description)`::
- Add `-f, \--force`.
+ Add `-f, --force`.
`OPT__QUIET(&int_var, description)`::
- Add `-q, \--quiet`.
+ Add `-q, --quiet`.
`OPT__VERBOSE(&int_var, description)`::
- Add `-v, \--verbose`.
+ Add `-v, --verbose`.
`OPT_GROUP(description)`::
Start an option group. `description` is a short string that
`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`.
+ Each use of `--option` increments `int_var`, starting from zero
+ (even if initially negative), and `--no-option` resets it to
+ zero. To determine if `--option` or `--no-option` was encountered at
+ all, initialize `int_var` to a negative value, and if it is still
+ negative after parse_options(), then neither `--option` nor
+ `--no-option` was seen.
`OPT_BIT(short, long, &int_var, description, mask)`::
Introduce a boolean 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.
- If used, set `ptr_var` to `ptr`.
-
`OPT_STRING(short, long, &str_var, arg_str, description)`::
Introduce an option with string argument.
The string argument is put into `str_var`.
+`OPT_STRING_LIST(short, long, &struct string_list, arg_str, description)`::
+ Introduce an option with string argument.
+ The string argument is stored as an element in `string_list`.
+ Use of `--no-option` will clear the list of preceding values.
+
`OPT_INTEGER(short, long, &int_var, description)`::
Introduce an option with integer argument.
The integer is put into `int_var`.
-`OPT_DATE(short, long, &int_var, description)`::
+`OPT_MAGNITUDE(short, long, &unsigned_long_var, description)`::
+ Introduce an option with a size argument. The argument must be a
+ non-negative integer and may include a suffix of 'k', 'm' or 'g' to
+ scale the provided value by 1024, 1024^2 or 1024^3 respectively.
+ The scaled value is put into `unsigned_long_var`.
+
+`OPT_DATE(short, long, ×tamp_t_var, description)`::
Introduce an option with date argument, see `approxidate()`.
- The timestamp is put into `int_var`.
+ The timestamp is put into `timestamp_t_var`.
+
+`OPT_EXPIRY_DATE(short, long, ×tamp_t_var, description)`::
+ Introduce an option with expiry date argument, see `parse_expiry_date()`.
+ The timestamp is put into `timestamp_t_var`.
`OPT_CALLBACK(short, long, &var, arg_str, description, func_ptr)`::
Introduce an option with argument.
Use it to hide deprecated options that are still to be recognized
and ignored silently.
+`OPT_PASSTHRU(short, long, &char_var, arg_str, description, flags)`::
+ Introduce an option that will be reconstructed into a char* string,
+ which must be initialized to NULL. This is useful when you need to
+ pass the command-line option to another command. Any previous value
+ will be overwritten, so this should only be used for options where
+ the last one specified on the command line wins.
+
+`OPT_PASSTHRU_ARGV(short, long, &argv_array_var, arg_str, description, flags)`::
+ Introduce an option where all instances of it on the command-line will
+ be reconstructed into an argv_array. This is useful when you need to
+ pass the command-line option, which can be specified multiple times,
+ to another command.
+
+`OPT_CMDMODE(short, long, &int_var, description, enum_val)`::
+ Define an "operation mode" option, only one of which in the same
+ group of "operating mode" options that share the same `int_var`
+ can be given by the user. `enum_val` is set to `int_var` when the
+ option is used, but an error is reported if other "operating mode"
+ option has already set its value to the same `int_var`.
+
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. `{apostrophe}e{apostrophe}` 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,
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
+ given by `opt` is the void pointer `opt->value`.
+ `*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
+ For example, do `*(unsigned long *)opt->value = 42;` to get 42
into an `unsigned long` variable.
* Return value `0` indicates success and non-zero return
--------
See `test-parse-options.c` and
-`builtin-add.c`,
-`builtin-clone.c`,
-`builtin-commit.c`,
-`builtin-fetch.c`,
-`builtin-fsck.c`,
-`builtin-rm.c`
+`builtin/add.c`,
+`builtin/clone.c`,
+`builtin/commit.c`,
+`builtin/fetch.c`,
+`builtin/fsck.c`,
+`builtin/rm.c`
for real-world examples.