mirror of
https://github.com/sheumann/hush.git
synced 2024-12-28 07:30:23 +00:00
2bf88a891f
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.
266 lines
8.3 KiB
C
266 lines
8.3 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* universal getopt_ulflags implementation for busybox
|
|
*
|
|
* Copyright (C) 2003 Vladimir Oleynik <dzo@simtreas.ru>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <getopt.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <stdlib.h>
|
|
#include "libbb.h"
|
|
|
|
/* Documentation !
|
|
|
|
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:
|
|
|
|
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.
|
|
|
|
The value of this flag is given by the position of the char in
|
|
const char *applet_opts so for example in this case:
|
|
|
|
flags = bb_getopt_ulflags(argc, argv, "rnug");
|
|
|
|
"r" will add 1
|
|
"n" will add 2
|
|
"u will add 4
|
|
"g" will add 8
|
|
|
|
and so on.
|
|
|
|
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:
|
|
|
|
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;
|
|
|
|
typedef struct {
|
|
unsigned char opt;
|
|
char list_flg;
|
|
unsigned long switch_on;
|
|
unsigned long switch_off;
|
|
unsigned long incongruously;
|
|
void **optarg; /* char **optarg or llist_t **optarg */
|
|
} t_complementaly;
|
|
|
|
/* You can set bb_applet_long_options for parse called long options */
|
|
|
|
static const struct option bb_default_long_options[] = {
|
|
/* { "help", 0, NULL, '?' }, */
|
|
{ 0, 0, 0, 0 }
|
|
};
|
|
|
|
const struct option *bb_applet_long_options = bb_default_long_options;
|
|
|
|
unsigned long
|
|
bb_getopt_ulflags (int argc, char **argv, const char *applet_opts, ...)
|
|
{
|
|
unsigned long flags = 0;
|
|
t_complementaly complementaly[sizeof(flags) * 8 + 1];
|
|
int c;
|
|
const unsigned char *s;
|
|
t_complementaly *on_off;
|
|
va_list p;
|
|
|
|
va_start (p, applet_opts);
|
|
|
|
/* skip GNU extension */
|
|
s = applet_opts;
|
|
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++;
|
|
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;
|
|
continue;
|
|
}
|
|
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--;
|
|
}
|
|
|
|
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;
|
|
}
|