#include <stdlib.h>
#include "libbb.h"
-/* Documentation !
+/* Documentation
unsigned long
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
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).
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
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"
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
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
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.
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
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.
*/
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