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In Bug 5, Tito writes:

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This is a first attempt to improve the comments of getopt_ulflags.c.
Maybe under some aspects the text could be refined, but so
far it is already usable and should help people who "avoided getopt_ulflags as the pest" to understand how it works.

This patch was created with the help of
Vodz, the author of the code, who explained me patiently
how getopt_ulflags works
and with the help of
Paul Fox, who corrected my broken english.

So thanks and merits should go to them also.
This commit is contained in:
Mike Frysinger 2005-04-18 22:42:58 +00:00
parent 91d8f0e892
commit 2bf88a891f
1 changed files with 208 additions and 114 deletions
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322
libbb/getopt_ulflags.c
View File

@ -26,146 +26,240 @@
#include <stdlib.h> #include <stdlib.h>
#include "libbb.h" #include "libbb.h"
/* /* Documentation !
You can set bb_opt_complementaly as string with one or more
complementaly or incongruously options. bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...)
If sequential founded option haved from this string
then your incongruously pairs unsets and complementaly make add sets. The command line options must be declared in const char
Format: *applet_opts as a string of chars, for example:
one char - option for check,
chars - complementaly option for add sets. flags = bb_getopt_ulflags(argc, argv, "rnug");
- chars - option triggered for unsets.
~ chars - option incongruously. If one of the given options is found a flag value is added to
* - option list, called add_to_list(*ptr_from_usaged, optarg) the unsigned long returned by bb_getopt_ulflags.
: - separator.
Example: du applet can have options "-s" and "-d size" The value of this flag is given by the position of the char in
If getopt found -s then -d option flag unset or if found -d then -s unset. const char *applet_opts so for example in this case:
For this result you must set bb_opt_complementaly = "s-d:d-s".
Result have last option flag only from called arguments. flags = bb_getopt_ulflags(argc, argv, "rnug");
Warning! You can check returned flag, pointer to "d:" argument seted
to own optarg always. "r" will add 1
Example two: cut applet must only one type of list may be specified, "n" will add 2
and -b, -c and -f incongruously option, overwited option is error also. "u will add 4
You must set bb_opt_complementaly = "b~cf:c~bf:f~bc". "g" will add 8
If called have more one specified, return value have error flag -
high bite set (0x80000000UL). and so on.
Example three: grep applet can have one or more "-e pattern" arguments.
You should use bb_getopt_ulflags() as If an argument is required by one of the options add a ":"
llist_t *paterns; after the char in const char *applet_opts and provide a pointer
bb_opt_complementaly = "e*"; where the arg could be stored if it is found, for example:
bb_getopt_ulflags (argc, argv, "e:", &paterns);
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);
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).
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).
"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:
bb_opt_complementaly = "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.
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.
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
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.
char *smax_print_depth;
bb_opt_complementaly = "s-d:d-s";
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
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_complementaly = "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 (0x80000000UL) so
that we can check for it:
if ((flags & 0x80000000UL)
bb_show_usage();
"*" A star after a char in bb_opt_complementaly means that the
option can occur multiple times:
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;
(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
root:x:0:0:root:/root:/bin/bash
user:x:500:500::/home/user:/bin/bash
*/ */
const char *bb_opt_complementaly; const char *bb_opt_complementaly;
typedef struct typedef struct {
{
unsigned char opt; unsigned char opt;
char list_flg; char list_flg;
unsigned long switch_on; unsigned long switch_on;
unsigned long switch_off; unsigned long switch_off;
unsigned long incongruously; unsigned long incongruously;
void **optarg; /* char **optarg or llist_t **optarg */ void **optarg; /* char **optarg or llist_t **optarg */
} t_complementaly; } t_complementaly;
/* You can set bb_applet_long_options for parse called long options */ /* You can set bb_applet_long_options for parse called long options */
static const struct option bb_default_long_options[] = { static const struct option bb_default_long_options[] = {
/* { "help", 0, NULL, '?' }, */ /* { "help", 0, NULL, '?' }, */
{ 0, 0, 0, 0 } { 0, 0, 0, 0 }
}; };
const struct option *bb_applet_long_options = bb_default_long_options; const struct option *bb_applet_long_options = bb_default_long_options;
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, ...)
{ {
unsigned long flags = 0; unsigned long flags = 0;
t_complementaly complementaly[sizeof(flags) * 8 + 1]; t_complementaly complementaly[sizeof(flags) * 8 + 1];
int c; int c;
const unsigned char *s; const unsigned char *s;
t_complementaly *on_off; t_complementaly *on_off;
va_list p; va_list p;
va_start (p, applet_opts); va_start (p, applet_opts);
/* skip GNU extension */ /* skip GNU extension */
s = applet_opts; s = applet_opts;
if(*s == '+' || *s == '-') if(*s == '+' || *s == '-')
s++;
c = 0;
on_off = complementaly;
for (; *s; s++) {
if(c >= (sizeof(flags)*8))
break;
on_off->opt = *s;
on_off->switch_on = (1 << c);
on_off->list_flg = 0;
on_off->switch_off = 0;
on_off->incongruously = 0;
on_off->optarg = NULL;
if (s[1] == ':') {
on_off->optarg = va_arg (p, void **);
do
s++; s++;
while (s[1] == ':');
}
on_off++;
c++;
}
on_off->opt = 0;
c = 0;
for (s = bb_opt_complementaly; s && *s; s++) {
t_complementaly *pair;
if (*s == ':') { c = 0;
c = 0; on_off = complementaly;
continue; for (; *s; s++) {
} if(c >= (sizeof(flags)*8))
if (c) break;
continue; on_off->opt = *s;
for (on_off = complementaly; on_off->opt; on_off++) on_off->switch_on = (1 << c);
if (on_off->opt == *s) on_off->list_flg = 0;
break; on_off->switch_off = 0;
pair = on_off; on_off->incongruously = 0;
for(s++; *s && *s != ':'; s++) { on_off->optarg = NULL;
if (*s == '-' || *s == '~') { if (s[1] == ':') {
c = *s; on_off->optarg = va_arg (p, void **);
} else if(*s == '*') { do
pair->list_flg++; s++;
} else { while (s[1] == ':');
unsigned long *pair_switch = &(pair->switch_on); }
on_off++;
if(c) c++;
pair_switch = c == '-' ? &(pair->switch_off) : &(pair->incongruously);
for (on_off = complementaly; on_off->opt; on_off++)
if (on_off->opt == *s) {
*pair_switch |= on_off->switch_on;
break;
}
}
}
s--;
}
while ((c = getopt_long (argc, argv, applet_opts,
bb_applet_long_options, NULL)) > 0) {
for (on_off = complementaly; on_off->opt != c; on_off++) {
if(!on_off->opt)
bb_show_usage ();
} }
if(flags & on_off->incongruously) on_off->opt = 0;
flags |= 0x80000000UL; c = 0;
flags &= ~on_off->switch_off; for (s = bb_opt_complementaly; s && *s; s++) {
flags |= on_off->switch_on; t_complementaly *pair;
if(on_off->list_flg) {
*(llist_t **)(on_off->optarg) = if (*s == ':') {
llist_add_to(*(llist_t **)(on_off->optarg), optarg); c = 0;
} else if (on_off->optarg) { continue;
*(char **)(on_off->optarg) = optarg; }
if (c)
continue;
for (on_off = complementaly; on_off->opt; on_off++)
if (on_off->opt == *s)
break;
pair = on_off;
for(s++; *s && *s != ':'; s++) {
if (*s == '-' || *s == '~') {
c = *s;
} else if(*s == '*') {
pair->list_flg++;
} else {
unsigned long *pair_switch = &(pair->switch_on);
if(c)
pair_switch = c == '-' ? &(pair->switch_off) : &(pair->incongruously);
for (on_off = complementaly; on_off->opt; on_off++)
if (on_off->opt == *s) {
*pair_switch |= on_off->switch_on;
break;
}
}
}
s--;
} }
}
return flags; while ((c = getopt_long (argc, argv, applet_opts,
bb_applet_long_options, NULL)) > 0) {
for (on_off = complementaly; on_off->opt != c; on_off++) {
if(!on_off->opt)
bb_show_usage ();
}
if(flags & on_off->incongruously)
flags |= 0x80000000UL;
flags &= ~on_off->switch_off;
flags |= on_off->switch_on;
if(on_off->list_flg) {
*(llist_t **)(on_off->optarg) =
llist_add_to(*(llist_t **)(on_off->optarg), optarg);
} else if (on_off->optarg) {
*(char **)(on_off->optarg) = optarg;
}
}
return flags;
} }