linux 里面写一些命令行小玩意儿有 getopt 这个函数方便使用，Windows 上是不自带的，从 libevent 的仓库里扣了出来
// getopt.h
#ifndef __GETOPT_H__
#define __GETOPT_H__
#ifdef __cplusplus
extern "C" {
#endif
extern int opterr; /* if error message should be printed */
extern int optind; /* index into parent argv vector */
extern int optopt; /* character checked for validity */
extern int optreset; /* reset getopt */
extern char *optarg; /* argument associated with option */
struct option
{
const char *name;
int has_arg;
int *flag;
int val;
};
#define no_argument 0
#define required_argument 1
#define optional_argument 2
int getopt(int, char**, const char*);
int getopt_long(int, char**, const char*, const struct option*, int*);
#ifdef __cplusplus
}
#endif
#endif /* __GETOPT_H__ */
然后是对应的实现
// getopt.c
/* $NetBSD: getopt.c,v 1.16 1999/12/02 13:15:56 kleink Exp $ */
/*
* Copyright (c) 1987, 1993, 1994, 1995
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#if 0
static char sccsid[] = "@(#)getopt.c 8.3 (Berkeley) 4/27/95";
#endif
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#define __P(x) x
#define _DIAGASSERT(x) assert(x)
#ifdef __weak_alias
__weak_alias(getopt,_getopt);
#endif
int opterr = 1, /* if error message should be printed */
optind = 1, /* index into parent argv vector */
optopt, /* character checked for validity */
optreset; /* reset getopt */
char *optarg; /* argument associated with option */
static char * _progname __P((char *));
int getopt_internal __P((int, char * const *, const char *));
static char *
_progname(nargv0)
char * nargv0;
{
char * tmp;
_DIAGASSERT(nargv0 != NULL);
tmp = strrchr(nargv0, '/');
if (tmp)
tmp++;
else
tmp = nargv0;
return(tmp);
}
#define BADCH (int)'?'
#define BADARG (int)':'
#define EMSG ""
/*
* getopt --
* Parse argc/argv argument vector.
*/
int
getopt(nargc, nargv, ostr)
int nargc;
char * const nargv[];
const char *ostr;
{
static char *__progname = 0;
static char *place = EMSG; /* option letter processing */
char *oli; /* option letter list index */
__progname = __progname?__progname:_progname(*nargv);
_DIAGASSERT(nargv != NULL);
_DIAGASSERT(ostr != NULL);
if (optreset || !*place) { /* update scanning pointer */
optreset = 0;
if (optind >= nargc || *(place = nargv[optind]) != '-') {
place = EMSG;
return (-1);
}
if (place[1] && *++place == '-' /* found "--" */
&& place[1] == '\0') {
++optind;
place = EMSG;
return (-1);
}
} /* option letter okay? */
if ((optopt = (int)*place++) == (int)':' ||
!(oli = strchr(ostr, optopt))) {
/*
* if the user didn't specify '-' as an option,
* assume it means -1.
*/
if (optopt == (int)'-')
return (-1);
if (!*place)
++optind;
if (opterr && *ostr != ':')
(void)fprintf(stderr,
"%s: illegal option -- %c\n", __progname, optopt);
return (BADCH);
}
if (*++oli != ':') { /* don't need argument */
optarg = NULL;
if (!*place)
++optind;
}
else { /* need an argument */
if (*place) /* no white space */
optarg = place;
else if (nargc <= ++optind) { /* no arg */
place = EMSG;
if (*ostr == ':')
return (BADARG);
if (opterr)
(void)fprintf(stderr,
"%s: option requires an argument -- %c\n",
__progname, optopt);
return (BADCH);
}
else /* white space */
optarg = nargv[optind];
place = EMSG;
++optind;
}
return (optopt); /* dump back option letter */
}
第二个实现
// getopt_long.c
/*
* Copyright (c) 1987, 1993, 1994, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "getopt.h"
extern int opterr; /* if error message should be printed */
extern int optind; /* index into parent argv vector */
extern int optopt; /* character checked for validity */
extern int optreset; /* reset getopt */
extern char *optarg; /* argument associated with option */
#define __P(x) x
#define _DIAGASSERT(x) assert(x)
static char * __progname __P((char *));
int getopt_internal __P((int, char * const *, const char *));
static char *
__progname(nargv0)
char * nargv0;
{
char * tmp;
_DIAGASSERT(nargv0 != NULL);
tmp = strrchr(nargv0, '/');
if (tmp)
tmp++;
else
tmp = nargv0;
return(tmp);
}
#define BADCH (int)'?'
#define BADARG (int)':'
#define EMSG ""
/*
* getopt --
* Parse argc/argv argument vector.
*/
int
getopt_internal(nargc, nargv, ostr)
int nargc;
char * const *nargv;
const char *ostr;
{
static char *place = EMSG; /* option letter processing */
char *oli; /* option letter list index */
_DIAGASSERT(nargv != NULL);
_DIAGASSERT(ostr != NULL);
if (optreset || !*place) { /* update scanning pointer */
optreset = 0;
if (optind >= nargc || *(place = nargv[optind]) != '-') {
place = EMSG;
return (-1);
}
if (place[1] && *++place == '-') { /* found "--" */
/* ++optind; */
place = EMSG;
return (-2);
}
} /* option letter okay? */
if ((optopt = (int)*place++) == (int)':' ||
!(oli = strchr(ostr, optopt))) {
/*
* if the user didn't specify '-' as an option,
* assume it means -1.
*/
if (optopt == (int)'-')
return (-1);
if (!*place)
++optind;
if (opterr && *ostr != ':')
(void)fprintf(stderr,
"%s: illegal option -- %c\n", __progname(nargv[0]), optopt);
return (BADCH);
}
if (*++oli != ':') { /* don't need argument */
optarg = NULL;
if (!*place)
++optind;
} else { /* need an argument */
if (*place) /* no white space */
optarg = place;
else if (nargc <= ++optind) { /* no arg */
place = EMSG;
if ((opterr) && (*ostr != ':'))
(void)fprintf(stderr,
"%s: option requires an argument -- %c\n",
__progname(nargv[0]), optopt);
return (BADARG);
} else /* white space */
optarg = nargv[optind];
place = EMSG;
++optind;
}
return (optopt); /* dump back option letter */
}
#if 0
/*
* getopt --
* Parse argc/argv argument vector.
*/
int
getopt2(nargc, nargv, ostr)
int nargc;
char * const *nargv;
const char *ostr;
{
int retval;
if ((retval = getopt_internal(nargc, nargv, ostr)) == -2) {
retval = -1;
++optind;
}
return(retval);
}
#endif
/*
* getopt_long --
* Parse argc/argv argument vector.
*/
int
getopt_long(nargc, nargv, options, long_options, index)
int nargc;
char ** nargv;
const char * options;
const struct option * long_options;
int * index;
{
int retval;
_DIAGASSERT(nargv != NULL);
_DIAGASSERT(options != NULL);
_DIAGASSERT(long_options != NULL);
/* index may be NULL */
if ((retval = getopt_internal(nargc, nargv, options)) == -2) {
char *current_argv = nargv[optind++] + 2, *has_equal;
int i, match = -1;
size_t current_argv_len;
if (*current_argv == '\0') {
return(-1);
}
if ((has_equal = strchr(current_argv, '=')) != NULL) {
current_argv_len = has_equal - current_argv;
has_equal++;
} else
current_argv_len = strlen(current_argv);
for (i = 0; long_options[i].name; i++) {
if (strncmp(current_argv, long_options[i].name, current_argv_len))
continue;
if (strlen(long_options[i].name) == current_argv_len) {
match = i;
break;
}
if (match == -1)
match = i;
}
if (match != -1) {
if (long_options[match].has_arg == required_argument ||
long_options[match].has_arg == optional_argument) {
if (has_equal)
optarg = has_equal;
else
optarg = nargv[optind++];
}
if ((long_options[match].has_arg == required_argument)
&& (optarg == NULL)) {
/*
* Missing argument, leading :
* indicates no error should be generated
*/
if ((opterr) && (*options != ':'))
(void)fprintf(stderr,
"%s: option requires an argument -- %s\n",
__progname(nargv[0]), current_argv);
return (BADARG);
}
} else { /* No matching argument */
if ((opterr) && (*options != ':'))
(void)fprintf(stderr,
"%s: illegal option -- %s\n", __progname(nargv[0]), current_argv);
return (BADCH);
}
if (long_options[match].flag) {
*long_options[match].flag = long_options[match].val;
retval = 0;
} else
retval = long_options[match].val;
if (index)
*index = match;
}
return(retval);
}