diff options
| -rw-r--r-- | libbb/getopt_ulflags.c | 101 |
1 files changed, 62 insertions, 39 deletions
diff --git a/libbb/getopt_ulflags.c b/libbb/getopt_ulflags.c index 24bdcb6..86cf453 100644 --- a/libbb/getopt_ulflags.c +++ b/libbb/getopt_ulflags.c @@ -28,6 +28,7 @@ /* Documentation ! +unsigned long bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) The command line options must be declared in const char @@ -35,24 +36,25 @@ bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) flags = bb_getopt_ulflags(argc, argv, "rnug"); - If one of the given options is found a flag value is added to - the unsigned long returned by bb_getopt_ulflags. + If one of the given options is found, a flag value is added to + the return value (an unsigned long). - The value of this flag is given by the position of the char in - const char *applet_opts so for example in this case: + The flag value is determined by the position of the char in + applet_opts string. For example, in the above case: flags = bb_getopt_ulflags(argc, argv, "rnug"); - "r" will add 1 - "n" will add 2 - "u will add 4 - "g" will add 8 + "r" will add 1 (bit 1 : 0x01) + "n" will add 2 (bit 2 : 0x02) + "u will add 4 (bit 3 : 0x03) + "g" will add 8 (bit 4 : 0x04) - and so on. + and so on. You can also look at the return value as a bit + field and each option sets one of bits. - If an argument is required by one of the options add a ":" - after the char in const char *applet_opts and provide a pointer - where the arg could be stored if it is found, for example: + ":" If one of the options requires an argument, then add a ":" + after the char in applet_opts and provide a pointer to store + the argument. For example: char *pointer_to_arg_for_a; char *pointer_to_arg_for_b; @@ -63,20 +65,43 @@ bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) &pointer_to_arg_for_a, &pointer_to_arg_for_b, &pointer_to_arg_for_c, &pointer_to_arg_for_d); - The type of the pointer (char* or llist_t *) can be influenced - by the "*" special character that can be set in const char - *bb_opt_complementaly (see below). + The type of the pointer (char* or llist_t *) may be controlled + by the "*" special character that is set in the external string + bb_opt_complementaly (see below for more info). + +static const struct option bb_default_long_options[] + + This struct allows you to define long options. The syntax for + declaring the array is just like that of getopt's longopts. + + static const struct option applet_long_options[] = { + { "verbose", 0, 0, "v" }, + { 0, 0, 0, 0 } + }; + bb_applet_long_options = applet_long_options; + + The first parameter is the long option that you would pass to + the applet (--verbose) in place of the short option (-v). The + second field determines whether the option has an argument. + You can set this to 0, 1, or 2, or you can use the long named + defines of no_argument, required_argument, and optional_argument. + Just set the third argument to '0' or 'NULL'. The last argument + is simply the short option without the dash of course. + + Note: a good applet will make long options configurable via the + config process and not a required feature. The current standard + is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS. const char *bb_opt_complementaly - ":" The colon (":") is used in bb_opt_complementaly as separator - between groups of two or more chars and/or groups of chars and - special characters (stating some conditions to be checked). + ":" The colon (":") is used to separate groups of two or more chars + and/or groups of chars and special characters (stating some + conditions to be checked). - "abc" If groups of two or more chars are specified the first char - is the main option and the other chars are secondary options - whose flags will be turned on if the main option is found even - if they are not specifed on the command line, for example: + "abc" If groups of two or more chars are specified, the first char + is the main option and the other chars are secondary options. + Their flags will be turned on if the main option is found even + if they are not specifed on the command line. For example: bb_opt_complementaly = "abc"; @@ -92,30 +117,28 @@ Special characters: to be unset (and ignored) if it is given on the command line. For example: - The du applet can have the options "-s" and "-d depth", if - bb_getopt_ulflags finds -s then -d is unset or if it finds -d + The du applet has the options "-s" and "-d depth". If + bb_getopt_ulflags finds -s, then -d is unset or if it finds -d then -s is unset. (Note: busybox implements the GNU - "--max-depth" option as "-d".) In this case bb_getopt_ulflags's - return value has no error flag set (0x80000000UL). To achieve - this result you must set bb_opt_complementaly = "s-d:d-s". - Only one flag value is added to bb_getopt_ulflags's return - value depending on the position of the options on the command - line. If one of the two options requires an argument pointer - (":" in const char *applet_opts as in "d:") optarg is set - accordingly. + "--max-depth" option as "-d".) To obtain this behavior, you + set bb_opt_complementaly = "s-d:d-s". Only one flag value is + added to bb_getopt_ulflags's return value depending on the + position of the options on the command line. If one of the + two options requires an argument pointer (":" in applet_opts + as in "d:") optarg is set accordingly. char *smax_print_depth; bb_opt_complementaly = "s-d:d-s"; - opt = bb_getopt_ulflags(argc, argv, "sd:" , &smax_print_depth); + opt = bb_getopt_ulflags(argc, argv, "sd:", &smax_print_depth); if (opt & 2) { max_print_depth = bb_xgetularg10_bnd(smax_print_depth, 0, INT_MAX); } - "~" A tilde between two options or between an option and a group - of options means that they are mutually exclusive. Unlike + "~" A tilde between two options, or between an option and a group + of options, means that they are mutually exclusive. Unlike the "-" case above, an error will be forced if the options are used together. @@ -128,7 +151,7 @@ Special characters: return value will have the error flag set (0x80000000UL) so that we can check for it: - if ((flags & 0x80000000UL) + if (flags & 0x80000000UL) bb_show_usage(); "*" A star after a char in bb_opt_complementaly means that the @@ -138,15 +161,15 @@ Special characters: The grep applet can have one or more "-e pattern" arguments. In this case you should use bb_getopt_ulflags() as follows: - llist_t *patterns=NULL; + llist_t *patterns = NULL; (this pointer must be initializated to NULL if the list is empty as required by *llist_add_to(llist_t *old_head, char *new_item).) bb_opt_complementaly = "e*"; - bb_getopt_ulflags (argc, argv, "e:", &patterns); - grep -e user -e root /etc/passwd + bb_getopt_ulflags(argc, argv, "e:", &patterns); + $ grep -e user -e root /etc/passwd root:x:0:0:root:/root:/bin/bash user:x:500:500::/home/user:/bin/bash |