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author | Denis Vlasenko | 2006-09-29 13:56:58 +0000 |
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committer | Denis Vlasenko | 2006-09-29 13:56:58 +0000 |
commit | f0d6cc8ca97454e64c041c571320d2288d1f2cd9 (patch) | |
tree | 79677c5dcb629bfa56f6fd8ea8bfa68d2fdee409 /libbb/getopt_ulflags.c | |
parent | b02ef82c99819607df32d3261cef1d674d67893a (diff) | |
download | busybox-f0d6cc8ca97454e64c041c571320d2288d1f2cd9.zip busybox-f0d6cc8ca97454e64c041c571320d2288d1f2cd9.tar.gz |
getopt_ulflags: fix indentation in comment (needs to be 8 _spaces_
in order to look correct to both 4 tab and 8 tab population).
Add comment about :: (which indicates optional argument).
Diffstat (limited to 'libbb/getopt_ulflags.c')
-rw-r--r-- | libbb/getopt_ulflags.c | 372 |
1 files changed, 189 insertions, 183 deletions
diff --git a/libbb/getopt_ulflags.c b/libbb/getopt_ulflags.c index 7ad2655..988f3f9 100644 --- a/libbb/getopt_ulflags.c +++ b/libbb/getopt_ulflags.c @@ -10,268 +10,274 @@ #include "libbb.h" #include <getopt.h> -/* Documentation +/* Documentation unsigned long bb_getopt_ulflags(int argc, char **argv, const char *applet_opts, ...) - The command line options must be declared in const char - *applet_opts as a string of chars, for example: + The command line options must be declared in const char + *applet_opts as a string of chars, for example: - flags = bb_getopt_ulflags(argc, argv, "rnug"); + flags = bb_getopt_ulflags(argc, argv, "rnug"); - If one of the given options is found, a flag value is added to - the return value (an unsigned long). + If one of the given options is found, a flag value is added to + the return value (an unsigned long). - The flag value is determined by the position of the char in - applet_opts string. For example, in the above 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"); + flags = bb_getopt_ulflags(argc, argv, "rnug"); - "r" will add 1 (bit 0) - "n" will add 2 (bit 1) - "u will add 4 (bit 2) - "g" will add 8 (bit 3) + "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 bit. + and so on. You can also look at the return value as a bit + field and each option sets one bit. - On exit, global variable optind is set so that if you - will do argc -= optind; argv += optind; then - argc will be equal to number of remaining non-option - arguments, first one would be in argv[0], next in argv[1] and so on - (options and their parameters will be moved into argv[] - positions prior to argv[optind]). + On exit, global variable optind is set so that if you + will do argc -= optind; argv += optind; then + argc will be equal to number of remaining non-option + arguments, first one would be in argv[0], next in argv[1] and so on + (options and their parameters will be moved into argv[] + positions prior to argv[optind]). ":" 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: + 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; - char *pointer_to_arg_for_c; - char *pointer_to_arg_for_d; + char *pointer_to_arg_for_a; + char *pointer_to_arg_for_b; + char *pointer_to_arg_for_c; + 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); + 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); - 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). + 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). + + "::" If option can have an *optional* argument, then add a "::" + after its char in applet_opts and provide a pointer to store + the argument. Note that optional arguments _must_ + immediately follow the option: -oparam, not -o param. "+" If the first character in the applet_opts string is a plus, - then option processing will stop as soon as a non-option is - encountered in the argv array. Useful for applets like env - which should not process arguments to subprograms: - env -i ls -d / - Here we want env to process just the '-i', not the '-d'. + then option processing will stop as soon as a non-option is + encountered in the argv array. Useful for applets like env + which should not process arguments to subprograms: + env -i ls -d / + Here we want env to process just the '-i', not the '-d'. 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)) + 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[] = { - //name,has_arg,flag,val - { "verbose", 0, 0, 'v' }, - { 0, 0, 0, 0 } - }; - bb_applet_long_options = applet_long_options; + static const struct option applet_long_options[] = { + //name,has_arg,flag,val + { "verbose", 0, 0, 'v' }, + { 0, 0, 0, 0 } + }; + bb_applet_long_options = applet_long_options; - 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 affects it too + 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 affects it too - 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. + 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_complementally - this should be bb_opt_complementary, but we'll just keep it as - bb_opt_complementally due to the Russian origins + this should be bb_opt_complementary, but we'll just keep it as + bb_opt_complementally due to the Russian origins ":" 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). + 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. - Their flags will be turned on if the main option is found even - if they are not specifed on the command line. For example: + 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_complementally = "abc"; - flags = bb_getopt_ulflags(argc, argv, "abcd") + bb_opt_complementally = "abc"; + flags = bb_getopt_ulflags(argc, argv, "abcd") - If getopt() finds "-a" on the command line, then - bb_getopt_ulflags's return value will be as if "-a -b -c" were - found. + If getopt() finds "-a" on the command line, then + bb_getopt_ulflags's return value will be as if "-a -b -c" were + found. "ww" Adjacent double options have a counter associated which indicates - 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" - - int w_counter = 0; - bb_opt_complementally = "ww"; - bb_getopt_ulflags(argc, argv, "w", &w_counter); - if (w_counter) - width = (w_counter == 1) ? 132 : INT_MAX; - else - get_terminal_width(...&width...); - - w_counter is a pointer to an integer. It has to be passed to - bb_getopt_ulflags() after all other option argument sinks. - - For example: accept multiple -v to indicate the level of verbosity - and for each -b optarg, add optarg to my_b. Finally, if b is given, - turn off c and vice versa: - - llist_t *my_b = NULL; - 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 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); + 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" + + int w_counter = 0; + bb_opt_complementally = "ww"; + bb_getopt_ulflags(argc, argv, "w", &w_counter); + if (w_counter) + width = (w_counter == 1) ? 132 : INT_MAX; + else + get_terminal_width(...&width...); + + w_counter is a pointer to an integer. It has to be passed to + bb_getopt_ulflags() after all other option argument sinks. + + For example: accept multiple -v to indicate the level of verbosity + and for each -b optarg, add optarg to my_b. Finally, if b is given, + turn off c and vice versa: + + llist_t *my_b = NULL; + 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 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); Special characters: "-" A dash between two options causes the second of the two - to be unset (and ignored) 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?] + [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 - 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".) To obtain this behavior, you - set bb_opt_complementally = "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. + For example: + 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".) To obtain this behavior, you + set bb_opt_complementally = "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; + char *smax_print_depth; - bb_opt_complementally = "s-d:d-s:x-x"; - opt = bb_getopt_ulflags(argc, argv, "sd:x", &smax_print_depth); + 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 usage\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 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: + 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"); + 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). + Allows any arguments to be given without a dash (./program w x) + as well as with a dash (./program -x). "-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 + by a single digit (0-9) means that at least N non-option + arguments must be present on the command line "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. + 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 - the "-" case above, an error will be forced if the options - are used together. - - For example: - The cut applet must have only one type of list specified, so - -b, -c and -f are mutally exclusive and should raise an error - if specified together. In this case you must set - bb_opt_complementally = "b--cf:c--bf:f--bc". If two of the - mutually exclusive options are found, bb_getopt_ulflags's - return value will have the error flag set (BB_GETOPT_ERROR) so - that we can check for it: - - if (flags & BB_GETOPT_ERROR) - bb_show_usage(); + of options, means that they are mutually exclusive. Unlike + the "-" case above, an error will be forced if the options + are used together. + + For example: + The cut applet must have only one type of list specified, so + -b, -c and -f are mutally exclusive and should raise an error + if specified together. In this case you must set + bb_opt_complementally = "b--cf:c--bf:f--bc". If two of the + mutually exclusive options are found, bb_getopt_ulflags's + return value will have the error flag set (BB_GETOPT_ERROR) so + that we can check for it: + + if (flags & BB_GETOPT_ERROR) + bb_show_usage(); "x--x" Variation of the above, it means that -x option should occur - at most once. + at most once. "?" 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. + 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 "?" 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. + 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. Each occurrence will be saved as - a llist_t element instead of char*. + 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. - In this case you should use bb_getopt_ulflags() as follows: + For example: + 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).) + (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_complementally = "e::"; + bb_opt_complementally = "e::"; - 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 + 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 "--" A double dash at the beginning of bb_opt_complementally means the - argv[1] string should always be treated as options, even if it isn't - prefixed with a "-". This is useful for special syntax in applets - such as "ar" and "tar": - tar xvf foo.tar + argv[1] string should always be treated as options, even if it isn't + prefixed with a "-". This is useful for special syntax in applets + such as "ar" and "tar": + tar xvf foo.tar "?" 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. + at least one of them is required to occur if the first option + occurs in preceding command line arguments. - For example from "id" applet: + For example from "id" applet: - // Don't allow -n -r -rn -ug -rug -nug -rnug - bb_opt_complementally = "r?ug:n?ug:?u--g:g--u"; - flags = bb_getopt_ulflags(argc, argv, "rnug"); + // Don't allow -n -r -rn -ug -rug -nug -rnug + bb_opt_complementally = "r?ug:n?ug:?u--g:g--u"; + flags = bb_getopt_ulflags(argc, argv, "rnug"); - This example allowed only: - $ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng + This example allowed only: + $ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng "X" A bb_opt_complementally group with just a single letter means - that 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: + that 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 is required - bb_opt_complementally = "K:S:?K--S:S--K"; - flags = bb_getopt_ulflags(argc, argv, "KS...); + // 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...); - 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. + 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. */ /* this should be bb_opt_complementary, but we'll just keep it as |