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Diffstat (limited to 'Documentation/technical/api-parse-options.txt')
| -rw-r--r-- | Documentation/technical/api-parse-options.txt | 75 |
1 files changed, 55 insertions, 20 deletions
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 3062389404..5a60bbfa7f 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -1,7 +1,7 @@ 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 @@ -29,9 +29,9 @@ that allow to change the behavior of a command. 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. @@ -41,6 +41,8 @@ The parse-options API allows: * Boolean long options can be 'negated' (or 'unset') by prepending `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 @@ -142,8 +144,12 @@ There are some macros to easily define options: `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. @@ -158,21 +164,28 @@ There are some macros to easily define options: `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)`:: - Introduce an option with date argument, see `approxidate()`. - The timestamp is put into `int_var`. +`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_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. @@ -185,8 +198,10 @@ There are some macros to easily define options: The filename will be prefixed by passing the filename along with the prefix argument of `parse_options()` to `prefix_filename()`. -`OPT_ARGUMENT(long, description)`:: +`OPT_ARGUMENT(long, &int_var, description)`:: Introduce a long-option argument that will be kept in `argv[]`. + If this option was seen, `int_var` will be set to one (except + if a `NULL` pointer was passed). `OPT_NUMBER_CALLBACK(&var, description, func_ptr)`:: Recognize numerical options like -123 and feed the integer as @@ -210,6 +225,26 @@ There are some macros to easily define options: 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, &strvec_var, arg_str, description, flags)`:: + Introduce an option where all instances of it on the command-line will + be reconstructed into a strvec. 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()`. @@ -269,10 +304,10 @@ Examples -------- 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. |