diff options
| -rw-r--r-- | libbb/getopt_ulflags.c | 113 |
1 files changed, 60 insertions, 53 deletions
diff --git a/libbb/getopt_ulflags.c b/libbb/getopt_ulflags.c index 199147b..76bdeed 100644 --- a/libbb/getopt_ulflags.c +++ b/libbb/getopt_ulflags.c @@ -26,7 +26,7 @@ #include <stdlib.h> #include "libbb.h" -/* Documentation ! +/* Documentation unsigned long bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) @@ -44,13 +44,13 @@ bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) flags = bb_getopt_ulflags(argc, argv, "rnug"); - "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) + "r" will add 1 (bit 0) + "n" will add 2 (bit 1) + "u will add 4 (bit 2) + "g" will add 8 (bit 3) - and so on. You can also look at the return value as a bit - field and each option sets one of bits. + and so on. You can also look at the return value as a bit + field and each option sets one bit. ":" If one of the options requires an argument, then add a ":" after the char in applet_opts and provide a pointer to store @@ -62,10 +62,10 @@ bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) char *pointer_to_arg_for_d; flags = bb_getopt_ulflags(argc, argv, "a:b:c:d:", - &pointer_to_arg_for_a, &pointer_to_arg_for_b, - &pointer_to_arg_for_c, &pointer_to_arg_for_d); + &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 *) may be controlled + The type of the pointer (char* or llist_t*) may be controlled by the "::" special separator that is set in the external string bb_opt_complementally (see below for more info). @@ -76,23 +76,24 @@ bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...) env -i ls -d / Here we want env to process just the '-i', not the '-d'. -static const struct option bb_default_long_options[] +const struct option *bb_applet_long_options This struct allows you to define long options. The syntax for declaring the array is just like that of getopt's longopts. (see getopt(3)) static const struct option applet_long_options[] = { - { "verbose", 0, 0, v }, + { "verbose", 0, 0, 'v' }, { 0, 0, 0, 0 } }; bb_applet_long_options = applet_long_options; - The last argument (val) can undefined from applet_opts. - If you use this, then: + The last member of struct option (val) typically is set to + matching short option from applet_opts. If there is no matching + char in applet_opts, then: - return bit have next position after short options - if has_arg is not "no_argument", use ptr for arg also - - bb_opt_complementally have effects for this too + - bb_opt_complementally affects it too Note: a good applet will make long options configurable via the config process and not a required feature. The current standard @@ -120,7 +121,7 @@ const char *bb_opt_complementally found. "ww" Adjacent double options have a counter associated which indicates - the number of occurances of the option. + the number of occurences of the option. For example the ps applet needs: if w is given once, GNU ps sets the width to 132, if w is given more than once, it is "unlimited" @@ -144,17 +145,18 @@ const char *bb_opt_complementally int verbose_level = 0; bb_opt_complementally = "vv:b::b-c:c-b"; f = bb_getopt_ulflags(argc, argv, "vb:c", &my_b, &verbose_level); - if((f & 2)) // -c after -b unset this -b flag - while (my_b) { dosomething_with(my_b->data) ; my_b = my_b->link; } - if(my_b) // but llist stored always if -b found + if((f & 2)) // -c after -b unsets -b flag + while(my_b) { dosomething_with(my_b->data) ; my_b = my_b->link; } + if(my_b) // but llist is stored if -b is specified free_llist(my_b); - if (verbose_level) bb_printf("verbose level is %d\n", verbose_level); + if(verbose_level) bb_printf("verbose level is %d\n", verbose_level); Special characters: "-" A dash between two options causes the second of the two - to be unset (and ignored or triggered) if it is given on - the command line. + to be unset (and ignored) if it is given on the command line. + + [FIXME: what if they are the same? like "x-x"? Is it ever useful?] For example: The du applet has the options "-s" and "-d depth". If @@ -172,28 +174,30 @@ Special characters: bb_opt_complementally = "s-d:d-s:x-x"; opt = bb_getopt_ulflags(argc, argv, "sd:x", &smax_print_depth); - if (opt & 2) { - max_print_depth = atoi(smax_print_depth); - } - if(opt & 4) - printf("Detected odd -x usaging\n"); + if (opt & 2) + max_print_depth = atoi(smax_print_depth); + if (opt & 4) + printf("Detected odd -x usage\n"); - "-" A dash as the first char in a bb_opt_complementally group means to - convert the arguments as option. Next char for this case can't set - [0-9], recomended use ':' or end of line. For example: + "-" A dash as the first char in a bb_opt_complementally group forces + all arguments to be treated as options, even if they have + no leading dashes. Next char in this case can't be a digit (0-9), + use ':' or end of line. For example: bb_opt_complementally = "-:w-x:x-w"; bb_getopt_ulflags(argc, argv, "wx"); Allows any arguments to be given without a dash (./program w x) - as well as with a dash (./program -x). Why unset -w see above. + as well as with a dash (./program -x). - "-N" A dash as the first char in a bb_opt_complementally group with - number 0-9 as one char is means check minimal arguments required. + "-N" A dash as the first char in a bb_opt_complementally group followed + by a single digit (0-9) means that at least N non-option + arguments must be present on the command line - "V-" A option with dash before colon or end line indicate: call - bb_show_usage if this option give, for example verbose - usage option. + "V-" An option with dash before colon or end-of-line results in + bb_show_usage being called if this option is encountered. + This is typically used to implement "print verbose usage message + and exit" option. "--" A double dash between two options, or between an option and a group of options, means that they are mutually exclusive. Unlike @@ -212,16 +216,17 @@ Special characters: if (flags & BB_GETOPT_ERROR) bb_show_usage(); - "?" A "ask" as the first char in a bb_opt_complementally group give: - if previous point set BB_GETOPT_ERROR, don't return and - call previous example internally. Next char for this case can't - set to [0-9], recomended use ':' or end of line. + "?" A "?" as the first char in a bb_opt_complementally group means: + if BB_GETOPT_ERROR is detected, don't return, call bb_show_usage + and exit instead. Next char after '?' can't be a digit. - "?N" A "ask" as the first char in a bb_opt_complementally group with - number 0-9 as one char is means check maximal arguments possible. + "?N" A "?" as the first char in a bb_opt_complementally group followed + by a single digit (0-9) means that at most N arguments must be present + on the command line. "::" A double colon after a char in bb_opt_complementally means that the - option can occur multiple times: + option can occur multiple times. Each occurrence will be saved as + a llist_t element instead of char*. For example: The grep applet can have one or more "-e pattern" arguments. @@ -245,8 +250,10 @@ Special characters: such as "ar" and "tar": tar xvf foo.tar - "?" An "ask" between main and group options causes the second of the two - to be depending required as or if first is given on the command line. + "?" An "?" between an option and a group of options means that + at least one of them is required to occur if the first option + occurs in preceding command line arguments. + For example from "id" applet: // Don't allow -n -r -rn -ug -rug -nug -rnug @@ -256,22 +263,22 @@ Special characters: This example allowed only: $ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng - "X" A one options in bb_opt_complementally group means - requires this option always with "or" logic if more one specified, - checked after switch off from complementally logic. + "X" A bb_opt_complementally group with just a single letter means + that this this option is required. If more than one such group exists, + at least one option is required to occur (not all of them). For example from "start-stop-daemon" applet: - // Don't allow -KS -SK, but -S or -K required + // Don't allow -KS -SK, but -S or -K is required bb_opt_complementally = "K:S:?K--S:S--K"; flags = bb_getopt_ulflags(argc, argv, "KS...); "x--x" give error if double or more used -x option - Don't forget ':' store. For example "?322-22-23X-x-a" interpretet as - "?3:22:-2:2-2:2-3Xa:2--x": max args is 3, count -2 usaged, min args is 2, - -2 option triggered, unset -3 and -X and -a if -2 any usaged, give error if - after -2 the -x option usaged. + Don't forget to use ':'. For example "?322-22-23X-x-a" is interpreted as + "?3:22:-2:2-2:2-3Xa:2--x": max 3 args; count uses of '-2'; min 2 args; + if there is a '-2' option then unset '-3', '-X' and '-a'; if there is + a '-2' and after it a '-x' then error out. */ |