/* Documentation !
+unsigned long
bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...)
The command line options must be declared in const char
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;
&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";
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.
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
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
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