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getopt_ulflags: fix indentation in comment (needs to be 8 _spaces_

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in order to look correct to both 4 tab and 8 tab population).
Add comment about :: (which indicates optional argument).
This commit is contained in:
Denis Vlasenko 2006-09-29 13:56:58 +00:00
parent b02ef82c99
commit f0d6cc8ca9
1 changed files with 183 additions and 177 deletions
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libbb/getopt_ulflags.c
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@ -10,268 +10,274 @@
#include "libbb.h" #include "libbb.h"
#include <getopt.h> #include <getopt.h>
/* Documentation /* Documentation
unsigned long unsigned long
bb_getopt_ulflags(int argc, char **argv, const char *applet_opts, ...) bb_getopt_ulflags(int argc, char **argv, const char *applet_opts, ...)
The command line options must be declared in const char The command line options must be declared in const char
*applet_opts as a string of chars, for example: *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 If one of the given options is found, a flag value is added to
the return value (an unsigned long). the return value (an unsigned long).
The flag value is determined by the position of the char in The flag value is determined by the position of the char in
applet_opts string. For example, in the above case: 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) "r" will add 1 (bit 0)
"n" will add 2 (bit 1) "n" will add 2 (bit 1)
"u will add 4 (bit 2) "u will add 4 (bit 2)
"g" will add 8 (bit 3) "g" will add 8 (bit 3)
and so on. You can also look at the return value as a bit and so on. You can also look at the return value as a bit
field and each option sets one bit. field and each option sets one bit.
On exit, global variable optind is set so that if you On exit, global variable optind is set so that if you
will do argc -= optind; argv += optind; then will do argc -= optind; argv += optind; then
argc will be equal to number of remaining non-option 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 arguments, first one would be in argv[0], next in argv[1] and so on
(options and their parameters will be moved into argv[] (options and their parameters will be moved into argv[]
positions prior to argv[optind]). positions prior to argv[optind]).
":" If one of the options requires an argument, then add a ":" ":" If one of the options requires an argument, then add a ":"
after the char in applet_opts and provide a pointer to store after the char in applet_opts and provide a pointer to store
the argument. For example: the argument. For example:
char *pointer_to_arg_for_a; char *pointer_to_arg_for_a;
char *pointer_to_arg_for_b; char *pointer_to_arg_for_b;
char *pointer_to_arg_for_c; char *pointer_to_arg_for_c;
char *pointer_to_arg_for_d; char *pointer_to_arg_for_d;
flags = bb_getopt_ulflags(argc, argv, "a:b:c: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_a, &pointer_to_arg_for_b,
&pointer_to_arg_for_c, &pointer_to_arg_for_d); &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 by the "::" special separator that is set in the external string
bb_opt_complementally (see below for more info). 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, "+" If the first character in the applet_opts string is a plus,
then option processing will stop as soon as a non-option is then option processing will stop as soon as a non-option is
encountered in the argv array. Useful for applets like env encountered in the argv array. Useful for applets like env
which should not process arguments to subprograms: which should not process arguments to subprograms:
env -i ls -d / env -i ls -d /
Here we want env to process just the '-i', not the '-d'. Here we want env to process just the '-i', not the '-d'.
const struct option *bb_applet_long_options const struct option *bb_applet_long_options
This struct allows you to define long options. The syntax for This struct allows you to define long options. The syntax for
declaring the array is just like that of getopt's longopts. declaring the array is just like that of getopt's longopts.
(see getopt(3)) (see getopt(3))
static const struct option applet_long_options[] = { static const struct option applet_long_options[] = {
//name,has_arg,flag,val //name,has_arg,flag,val
{ "verbose", 0, 0, 'v' }, { "verbose", 0, 0, 'v' },
{ 0, 0, 0, 0 } { 0, 0, 0, 0 }
}; };
bb_applet_long_options = applet_long_options; bb_applet_long_options = applet_long_options;
The last member of struct option (val) typically is set to The last member of struct option (val) typically is set to
matching short option from applet_opts. If there is no matching matching short option from applet_opts. If there is no matching
char in applet_opts, then: char in applet_opts, then:
- return bit have next position after short options - return bit have next position after short options
- if has_arg is not "no_argument", use ptr for arg also - if has_arg is not "no_argument", use ptr for arg also
- bb_opt_complementally affects it too - bb_opt_complementally affects it too
Note: a good applet will make long options configurable via the Note: a good applet will make long options configurable via the
config process and not a required feature. The current standard config process and not a required feature. The current standard
is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS. is to name the config option CONFIG_FEATURE_<applet>_LONG_OPTIONS.
const char *bb_opt_complementally const char *bb_opt_complementally
this should be bb_opt_complementary, but we'll just keep it as this should be bb_opt_complementary, but we'll just keep it as
bb_opt_complementally due to the Russian origins bb_opt_complementally due to the Russian origins
":" The colon (":") is used to separate groups of two or more chars ":" The colon (":") is used to separate groups of two or more chars
and/or groups of chars and special characters (stating some and/or groups of chars and special characters (stating some
conditions to be checked). conditions to be checked).
"abc" If groups of two or more chars are specified, the first char "abc" If groups of two or more chars are specified, the first char
is the main option and the other chars are secondary options. is the main option and the other chars are secondary options.
Their flags will be turned on if the main option is found even Their flags will be turned on if the main option is found even
if they are not specifed on the command line. For example: if they are not specifed on the command line. For example:
bb_opt_complementally = "abc"; bb_opt_complementally = "abc";
flags = bb_getopt_ulflags(argc, argv, "abcd") flags = bb_getopt_ulflags(argc, argv, "abcd")
If getopt() finds "-a" on the command line, then If getopt() finds "-a" on the command line, then
bb_getopt_ulflags's return value will be as if "-a -b -c" were bb_getopt_ulflags's return value will be as if "-a -b -c" were
found. found.
"ww" Adjacent double options have a counter associated which indicates "ww" Adjacent double options have a counter associated which indicates
the number of occurences of the option. the number of occurences of the option.
For example the ps applet needs: For example the ps applet needs:
if w is given once, GNU ps sets the width to 132, if w is given once, GNU ps sets the width to 132,
if w is given more than once, it is "unlimited" if w is given more than once, it is "unlimited"
int w_counter = 0; int w_counter = 0;
bb_opt_complementally = "ww"; bb_opt_complementally = "ww";
bb_getopt_ulflags(argc, argv, "w", &w_counter); bb_getopt_ulflags(argc, argv, "w", &w_counter);
if (w_counter) if (w_counter)
width = (w_counter == 1) ? 132 : INT_MAX; width = (w_counter == 1) ? 132 : INT_MAX;
else else
get_terminal_width(...&width...); get_terminal_width(...&width...);
w_counter is a pointer to an integer. It has to be passed to w_counter is a pointer to an integer. It has to be passed to
bb_getopt_ulflags() after all other option argument sinks. bb_getopt_ulflags() after all other option argument sinks.
For example: accept multiple -v to indicate the level of verbosity 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, and for each -b optarg, add optarg to my_b. Finally, if b is given,
turn off c and vice versa: turn off c and vice versa:
llist_t *my_b = NULL; llist_t *my_b = NULL;
int verbose_level = 0; int verbose_level = 0;
bb_opt_complementally = "vv:b::b-c:c-b"; bb_opt_complementally = "vv:b::b-c:c-b";
f = bb_getopt_ulflags(argc, argv, "vb:c", &my_b, &verbose_level); f = bb_getopt_ulflags(argc, argv, "vb:c", &my_b, &verbose_level);
if (f & 2) // -c after -b unsets -b flag if (f & 2) // -c after -b unsets -b flag
while (my_b) { dosomething_with(my_b->data); my_b = my_b->link; } while (my_b) { dosomething_with(my_b->data); my_b = my_b->link; }
if (my_b) // but llist is stored if -b is specified if (my_b) // but llist is stored if -b is specified
free_llist(my_b); 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: Special characters:
"-" A dash between two options causes the second of the two "-" 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: For example:
The du applet has the options "-s" and "-d depth". If 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 bb_getopt_ulflags finds -s, then -d is unset or if it finds -d
then -s is unset. (Note: busybox implements the GNU then -s is unset. (Note: busybox implements the GNU
"--max-depth" option as "-d".) To obtain this behavior, you "--max-depth" option as "-d".) To obtain this behavior, you
set bb_opt_complementally = "s-d:d-s". Only one flag value is set bb_opt_complementally = "s-d:d-s". Only one flag value is
added to bb_getopt_ulflags's return value depending on the added to bb_getopt_ulflags's return value depending on the
position of the options on the command line. If one of the position of the options on the command line. If one of the
two options requires an argument pointer (":" in applet_opts two options requires an argument pointer (":" in applet_opts
as in "d:") optarg is set accordingly. as in "d:") optarg is set accordingly.
char *smax_print_depth; char *smax_print_depth;
bb_opt_complementally = "s-d:d-s:x-x"; bb_opt_complementally = "s-d:d-s:x-x";
opt = bb_getopt_ulflags(argc, argv, "sd:x", &smax_print_depth); opt = bb_getopt_ulflags(argc, argv, "sd:x", &smax_print_depth);
if (opt & 2) if (opt & 2)
max_print_depth = atoi(smax_print_depth); max_print_depth = atoi(smax_print_depth);
if (opt & 4) if (opt & 4)
printf("Detected odd -x usage\n"); printf("Detected odd -x usage\n");
"-" A dash as the first char in a bb_opt_complementally group forces "-" A dash as the first char in a bb_opt_complementally group forces
all arguments to be treated as options, even if they have 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), no leading dashes. Next char in this case can't be a digit (0-9),
use ':' or end of line. For example: use ':' or end of line. For example:
bb_opt_complementally = "-:w-x:x-w"; bb_opt_complementally = "-:w-x:x-w";
bb_getopt_ulflags(argc, argv, "wx"); bb_getopt_ulflags(argc, argv, "wx");
Allows any arguments to be given without a dash (./program w x) Allows any arguments to be given without a dash (./program w x)
as well as with a dash (./program -x). as well as with a dash (./program -x).
"-N" A dash as the first char in a bb_opt_complementally group followed "-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 by a single digit (0-9) means that at least N non-option
arguments must be present on the command line arguments must be present on the command line
"V-" An option with dash before colon or end-of-line results in "V-" An option with dash before colon or end-of-line results in
bb_show_usage being called if this option is encountered. bb_show_usage being called if this option is encountered.
This is typically used to implement "print verbose usage message This is typically used to implement "print verbose usage message
and exit" option. and exit" option.
"--" A double dash between two options, or between an option and a group "--" A double dash between two options, or between an option and a group
of options, means that they are mutually exclusive. Unlike of options, means that they are mutually exclusive. Unlike
the "-" case above, an error will be forced if the options the "-" case above, an error will be forced if the options
are used together. are used together.
For example: For example:
The cut applet must have only one type of list specified, so The cut applet must have only one type of list specified, so
-b, -c and -f are mutally exclusive and should raise an error -b, -c and -f are mutally exclusive and should raise an error
if specified together. In this case you must set if specified together. In this case you must set
bb_opt_complementally = "b--cf:c--bf:f--bc". If two of the bb_opt_complementally = "b--cf:c--bf:f--bc". If two of the
mutually exclusive options are found, bb_getopt_ulflags's mutually exclusive options are found, bb_getopt_ulflags's
return value will have the error flag set (BB_GETOPT_ERROR) so return value will have the error flag set (BB_GETOPT_ERROR) so
that we can check for it: that we can check for it:
if (flags & BB_GETOPT_ERROR) if (flags & BB_GETOPT_ERROR)
bb_show_usage(); bb_show_usage();
"x--x" Variation of the above, it means that -x option should occur "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: "?" 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 if BB_GETOPT_ERROR is detected, don't return, call bb_show_usage
and exit instead. Next char after '?' can't be a digit. and exit instead. Next char after '?' can't be a digit.
"?N" A "?" as the first char in a bb_opt_complementally group followed "?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 by a single digit (0-9) means that at most N arguments must be present
on the command line. on the command line.
"::" A double colon after a char in bb_opt_complementally means that the "::" A double colon after a char in bb_opt_complementally means that the
option can occur multiple times. Each occurrence will be saved as option can occur multiple times. Each occurrence will be saved as
a llist_t element instead of char*. a llist_t element instead of char*.
For example: For example:
The grep applet can have one or more "-e pattern" arguments. The grep applet can have one or more "-e pattern" arguments.
In this case you should use bb_getopt_ulflags() as follows: 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 (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).) 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); bb_getopt_ulflags(argc, argv, "e:", &patterns);
$ grep -e user -e root /etc/passwd $ grep -e user -e root /etc/passwd
root:x:0:0:root:/root:/bin/bash root:x:0:0:root:/root:/bin/bash
user:x:500:500::/home/user:/bin/bash user:x:500:500::/home/user:/bin/bash
"--" A double dash at the beginning of bb_opt_complementally means the "--" 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 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 prefixed with a "-". This is useful for special syntax in applets
such as "ar" and "tar": such as "ar" and "tar":
tar xvf foo.tar tar xvf foo.tar
"?" An "?" between an option and a group of options means that "?" An "?" between an option and a group of options means that
at least one of them is required to occur if the first option at least one of them is required to occur if the first option
occurs in preceding command line arguments. 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 // Don't allow -n -r -rn -ug -rug -nug -rnug
bb_opt_complementally = "r?ug:n?ug:?u--g:g--u"; bb_opt_complementally = "r?ug:n?ug:?u--g:g--u";
flags = bb_getopt_ulflags(argc, argv, "rnug"); flags = bb_getopt_ulflags(argc, argv, "rnug");
This example allowed only: This example allowed only:
$ id; id -u; id -g; id -ru; id -nu; id -rg; id -ng; id -rnu; id -rng $ 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 "X" A bb_opt_complementally group with just a single letter means
that this option is required. If more than one such group exists, that this option is required. If more than one such group exists,
at least one option is required to occur (not all of them). at least one option is required to occur (not all of them).
For example from "start-stop-daemon" applet: For example from "start-stop-daemon" applet:
// Don't allow -KS -SK, but -S or -K is required // Don't allow -KS -SK, but -S or -K is required
bb_opt_complementally = "K:S:?K--S:S--K"; bb_opt_complementally = "K:S:?K--S:S--K";
flags = bb_getopt_ulflags(argc, argv, "KS...); 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 /* this should be bb_opt_complementary, but we'll just keep it as