GetOpt参数解析库使用介绍
本人在公司项目开发中遇到一个客户端拉起另外一个客户端场景，在最初拉起参数相对较简单时通过简单的参数判断即可符合需求，但随着业务和参数数量增多时，简单的判断已不再满足实际场景，同时也会增加后期扩展的难度，因此寻求一种基于C/C++开发的参数解析库。
网上资料搜索中，主流方式包括了Google的glags、Boost的tclap、GNU中的GetOpt；相比之下因为GetOpt无须引入新的第三方库，能快速满足业务需求，因此该库成为当时开发首选；GetOpt库属于Linux自带的C++库，在Windows平台使用时需要自己手动导入该库的相关文件。
功能介绍
GetOpt参数解析库主要包含了三种函数，分别适用于不同的场景，下面针对这三种场景进行简单的功能介绍：
getopt: 获取短参数，它可以获取-a，-l类型的短参数，也可以-al合并的获取到a和l
getopt_long: 在getopt的基础上获取长参数，它还可以获取--help这种参数
getopt_long_only: 也是在上一个函数基础上有所增加，输入长参数可以不用输入两个--，而是可以直接用-help
#include <unistd.h>
int getopt(int argc, char * const argv[],const char *optstring);
#include <getopt.h>
int getopt_long(int argc, char * const argv[],const char *optstring,const struct option *longopts, int *longindex)
int getopt_long_only(int argc, char * const argv[],const char *optstring,const struct option *longopts, int *longindex)
参数介绍
- argc和argv 就是传递给main函数的两个参数，argv就是程序运行时的程序名以及它的参数，是一个字符串数组，argc就是这个字符串数组的长度
- optstring 指定需要解析的短参数，比如"abc:d:e::"表示有abcde这5种参数，而且ab不带参数，c带参数(后面跟的:表示后面必须跟一个参数)，e可带可不带参数(后面跟的::表示选项参数是可选的，如果带参数必须紧挨着选项，也就是-exxx，不能有空格隔开如-e xxx，隔开则视为没有带参数)，选项参数由optarg指向
- longopts 指向option数组，包含了长选项的信息，数组最后一个元素（结构体）必须全部为0，下一节详细介绍这个结构体
- longindex 如果不是null，那么将解析参数时将把它指向的变量设为对应的longopts数组的下标
option结构体
struct option {
const char *name; // --<name> name of the long option
int has_arg; // no_argument (or 0), required_argument (or 1), optional_argument (or 2)
int *flag; // set *flag to val and returns 0 if not null
int val; // value to return or to load into *flag
}
- name 表示长选项的名字，使用时就是用--<name>的形式
- has_arg 用来指示这个选项的参数要求，no_argument或者0表示不带参数，required_argument或者1表示必须带参数，optional_argument或者2表示参数是可选的(可选的参数要带参数的话必须是--opt=param形式，不能用空格隔开，要用等于)
- flag 通常设为0，若不为0,那么解析参数时将会把*flag设置为val，然后函数返回0
- val 解析到参数时函数返回的值，或者设置*flag的值，通常把它设为对应的短参数字符
错误参数返回
getopt库在使用中主要会出现两种错误：
- 一个是出现不认识的选项；
- 需要带参数的选项没有带参数；
- 默认情况，遇到错误，输出错误信息，把出错的那个选项保存到optopt，然后返回?
- 如果opterr设为了0，则不输出错误信息，可以通过是否返回?来判定是否出错(默认情况opterr非0)
- 如果optstring的第一个字符(也可能是第二个，如果开头有+-的话)是:，那么也不会输出错误信息，然后会返回:表示缺少选项参数或者返回?表示出现不认识的选项(这样就能把两种错误区分开了)
Demo示例
#pragma once
#include <iostream>
#include <string>
#include "GlobalDefine.h"
#include "getopt.h"//用于命令行参数获取
static struct option g_options[] =
{
{"type", required_argument, NULL, 'a'},
{"token", required_argument, NULL, 'b'},
{"AlgId", required_argument, NULL, 'c'},
{"AlgRecordId", required_argument, NULL, 'd'},
{"Platform", required_argument, NULL, 'e'},
{NULL, 0, NULL, 0}
};
bool ParseLaunchParams(int argc, char *argv[], LaunchToolParams& stLaunchToolParams)
{
int ch;
opterr = 0;
while ((ch = getopt_long_only(argc, argv, "a::b:c::d::e::", g_options, NULL)) != -1)
{
switch ((char)ch)
{
case 'a':
stLaunchToolParams.nType = stoi(optarg);
break;
case 'b':
stLaunchToolParams.strUserToken = QString(optarg);
break;
case 'c':
stLaunchToolParams.lAlgApplicationId = stol(optarg);
break;
case 'd':
stLaunchToolParams.lAlgApplicationRecordId = stol(optarg);
break;
case 'e':
stLaunchToolParams.nPlatform = stoi(optarg);
break;
default:
return false;
}
}
return !stLaunchToolParams.strUserToken.isEmpty();
}
getopt相关代码
getopt.h
/* Declarations for getopt.
Copyright (C) 1989-1994,1996-1999,2001,2003,2004,2009,2010
Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _GETOPT_H
#ifndef __need_getopt
# define _GETOPT_H 1
#endif
/* If __GNU_LIBRARY__ is not already defined, either we are being used
standalone, or this is the first header included in the source file.
If we are being used with glibc, we need to include <features.h>, but
that does not exist if we are standalone. So: if __GNU_LIBRARY__ is
not defined, include <ctype.h>, which will pull in <features.h> for us
if it's from glibc. (Why ctype.h? It's guaranteed to exist and it
doesn't flood the namespace with stuff the way some other headers do.) */
#if !defined __GNU_LIBRARY__
# include <ctype.h>
#endif
#ifndef __THROW
# ifndef __GNUC_PREREQ
# define __GNUC_PREREQ(maj, min) (0)
# endif
# if defined __cplusplus && __GNUC_PREREQ (2,8)
# define __THROW throw ()
# else
# define __THROW
# endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* For communication from `getopt' to the caller.
When `getopt' finds an option that takes an argument,
the argument value is returned here.
Also, when `ordering' is RETURN_IN_ORDER,
each non-option ARGV-element is returned here. */
extern char *optarg;
/* Index in ARGV of the next element to be scanned.
This is used for communication to and from the caller
and for communication between successive calls to `getopt'.
On entry to `getopt', zero means this is the first call; initialize.
When `getopt' returns -1, this is the index of the first of the
non-option elements that the caller should itself scan.
Otherwise, `optind' communicates from one call to the next
how much of ARGV has been scanned so far. */
extern int optind;
/* Callers store zero here to inhibit the error message `getopt' prints
for unrecognized options. */
extern int opterr;
/* Set to an option character which was unrecognized. */
extern int optopt;
#ifndef __need_getopt
/* Describe the long-named options requested by the application.
The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
of `struct option' terminated by an element containing a name which is
zero.
The field `has_arg' is:
no_argument (or 0) if the option does not take an argument,
required_argument (or 1) if the option requires an argument,
optional_argument (or 2) if the option takes an optional argument.
If the field `flag' is not NULL, it points to a variable that is set
to the value given in the field `val' when the option is found, but
left unchanged if the option is not found.
To have a long-named option do something other than set an `int' to
a compiled-in constant, such as set a value from `optarg', set the
option's `flag' field to zero and its `val' field to a nonzero
value (the equivalent single-letter option character, if there is
one). For long options that have a zero `flag' field, `getopt'
returns the contents of the `val' field. */
struct option
{
const char *name;
/* has_arg can't be an enum because some compilers complain about
type mismatches in all the code that assumes it is an int. */
int has_arg;
int *flag;
int val;
};
/* Names for the values of the `has_arg' field of `struct option'. */
# define no_argument 0
# define required_argument 1
# define optional_argument 2
#endif /* need getopt */
/* Get definitions and prototypes for functions to process the
arguments in ARGV (ARGC of them, minus the program name) for
options given in OPTS.
Return the option character from OPTS just read. Return -1 when
there are no more options. For unrecognized options, or options
missing arguments, `optopt' is set to the option letter, and '?' is
returned.
The OPTS string is a list of characters which are recognized option
letters, optionally followed by colons, specifying that that letter
takes an argument, to be placed in `optarg'.
If a letter in OPTS is followed by two colons, its argument is
optional. This behavior is specific to the GNU `getopt'.
The argument `--' causes premature termination of argument
scanning, explicitly telling `getopt' that there are no more
options.
If OPTS begins with `--', then non-option arguments are treated as
arguments to the option '\0'. This behavior is specific to the GNU
`getopt'. */
#ifdef __GNU_LIBRARY__
/* Many other libraries have conflicting prototypes for getopt, with
differences in the consts, in stdlib.h. To avoid compilation
errors, only prototype getopt for the GNU C library. */
extern int getopt(int ___argc, char *const *___argv, const char *__shortopts)
__THROW;
# if defined __need_getopt && defined __USE_POSIX2 \
&& !defined __USE_POSIX_IMPLICITLY && !defined __USE_GNU
/* The GNU getopt has more functionality than the standard version. The
additional functionality can be disable at runtime. This redirection
helps to also do this at runtime. */
# ifdef __REDIRECT
extern int __REDIRECT_NTH(getopt, (int ___argc, char *const *___argv,
const char *__shortopts),
__posix_getopt);
# else
extern int __posix_getopt(int ___argc, char *const *___argv,
const char *__shortopts) __THROW;
# define getopt __posix_getopt
# endif
# endif
#else /* not __GNU_LIBRARY__ */
extern int getopt();
#endif /* __GNU_LIBRARY__ */
#ifndef __need_getopt
extern int getopt_long(int ___argc, char *const *___argv,
const char *__shortopts,
const struct option *__longopts, int *__longind)
__THROW;
extern int getopt_long_only(int ___argc, char *const *___argv,
const char *__shortopts,
const struct option *__longopts, int *__longind)
__THROW;
#endif
#ifdef __cplusplus
}
#endif
/* Make sure we later can get all the definitions and declarations. */
#undef __need_getopt
#endif /* getopt.h */
getopt.c
/* Getopt for GNU.
NOTE: getopt is now part of the C library, so if you don't know what
"Keep this file name-space clean" means, talk to drepper@gnu.org
before changing it!
Copyright (C) 1987,88,89,90,91,92,93,94,95,96,98,99,2000,2001
Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>.
Ditto for AIX 3.2 and <stdlib.h>. */
#ifndef _NO_PROTO
# define _NO_PROTO
#endif
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#if !defined __STDC__ || !__STDC__
/* This is a separate conditional since some stdc systems
reject `defined (const)'. */
# ifndef const
# define const
# endif
#endif
#include <stdio.h>
/* Comment out all this code if we are using the GNU C Library, and are not
actually compiling the library itself. This code is part of the GNU C
Library, but also included in many other GNU distributions. Compiling
and linking in this code is a waste when using the GNU C library
(especially if it is a shared library). Rather than having every GNU
program understand `configure --with-gnu-libc' and omit the object files,
it is simpler to just do this in the source for each such file. */
#define GETOPT_INTERFACE_VERSION 2
#if !defined _LIBC && defined __GLIBC__ && __GLIBC__ >= 2
# include <gnu-versions.h>
# if _GNU_GETOPT_INTERFACE_VERSION == GETOPT_INTERFACE_VERSION
# define ELIDE_CODE
# endif
#endif
#ifndef ELIDE_CODE
/* This needs to come after some library #include
to get __GNU_LIBRARY__ defined. */
#ifdef __GNU_LIBRARY__
/* Don't include stdlib.h for non-GNU C libraries because some of them
contain conflicting prototypes for getopt. */
# include <stdlib.h>
# include <unistd.h>
#endif /* GNU C library. */
#ifdef VMS
# include <unixlib.h>
# if HAVE_STRING_H - 0
# include <string.h>
# endif
#endif
#ifndef _
/* This is for other GNU distributions with internationalized messages. */
# if (HAVE_LIBINTL_H && ENABLE_NLS) || defined _LIBC
# include <libintl.h>
# ifndef _
# define _(msgid) gettext (msgid)
# endif
# else
# define _(msgid) (msgid)
# endif
# if defined _LIBC && defined USE_IN_LIBIO
# include <wchar.h>
# endif
#endif
/* This version of `getopt' appears to the caller like standard Unix `getopt'
but it behaves differently for the user, since it allows the user
to intersperse the options with the other arguments.
As `getopt' works, it permutes the elements of ARGV so that,
when it is done, all the options precede everything else. Thus
all application programs are extended to handle flexible argument order.
Setting the environment variable POSIXLY_CORRECT disables permutation.
Then the behavior is completely standard.
GNU application programs can use a third alternative mode in which
they can distinguish the relative order of options and other arguments. */
#include "getopt.h"
/* For communication from `getopt' to the caller.
When `getopt' finds an option that takes an argument,
the argument value is returned here.
Also, when `ordering' is RETURN_IN_ORDER,
each non-option ARGV-element is returned here. */
char *optarg;
/* Index in ARGV of the next element to be scanned.
This is used for communication to and from the caller
and for communication between successive calls to `getopt'.
On entry to `getopt', zero means this is the first call; initialize.
When `getopt' returns -1, this is the index of the first of the
non-option elements that the caller should itself scan.
Otherwise, `optind' communicates from one call to the next
how much of ARGV has been scanned so far. */
/* 1003.2 says this must be 1 before any call. */
int optind = 1;
/* Formerly, initialization of getopt depended on optind==0, which
causes problems with re-calling getopt as programs generally don't
know that. */
int __getopt_initialized;
/* The next char to be scanned in the option-element
in which the last option character we returned was found.
This allows us to pick up the scan where we left off.
If this is zero, or a null string, it means resume the scan
by advancing to the next ARGV-element. */
static char *nextchar;
/* Callers store zero here to inhibit the error message
for unrecognized options. */
int opterr = 1;
/* Set to an option character which was unrecognized.
This must be initialized on some systems to avoid linking in the
system's own getopt implementation. */
int optopt = '?';
/* Describe how to deal with options that follow non-option ARGV-elements.
If the caller did not specify anything,
the default is REQUIRE_ORDER if the environment variable
POSIXLY_CORRECT is defined, PERMUTE otherwise.
REQUIRE_ORDER means don't recognize them as options;
stop option processing when the first non-option is seen.
This is what Unix does.
This mode of operation is selected by either setting the environment
variable POSIXLY_CORRECT, or using `+' as the first character
of the list of option characters.
PERMUTE is the default. We permute the contents of ARGV as we scan,
so that eventually all the non-options are at the end. This allows options
to be given in any order, even with programs that were not written to
expect this.
RETURN_IN_ORDER is an option available to programs that were written
to expect options and other ARGV-elements in any order and that care about
the ordering of the two. We describe each non-option ARGV-element
as if it were the argument of an option with character code 1.
Using `-' as the first character of the list of option characters
selects this mode of operation.
The special argument `--' forces an end of option-scanning regardless
of the value of `ordering'. In the case of RETURN_IN_ORDER, only
`--' can cause `getopt' to return -1 with `optind' != ARGC. */
static enum
{
REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
} ordering;
/* Value of POSIXLY_CORRECT environment variable. */
static char *posixly_correct;
#ifdef __GNU_LIBRARY__
/* We want to avoid inclusion of string.h with non-GNU libraries
because there are many ways it can cause trouble.
On some systems, it contains special magic macros that don't work
in GCC. */
# include <string.h>
# define my_index strchr
#else
#define HAVE_STRING_H 1
# if HAVE_STRING_H
# include <string.h>
# else
# include <strings.h>
# endif
/* Avoid depending on library functions or files
whose names are inconsistent. */
#ifndef getenv
extern char *getenv();
#endif
static char *
my_index(str, chr)
const char *str;
int chr;
{
while (*str)
{
if (*str == chr)
return (char *)str;
str++;
}
return 0;
}
/* If using GCC, we can safely declare strlen this way.
If not using GCC, it is ok not to declare it. */
#ifdef __GNUC__
/* Note that Motorola Delta 68k R3V7 comes with GCC but not stddef.h.
That was relevant to code that was here before. */
# if (!defined __STDC__ || !__STDC__) && !defined strlen
/* gcc with -traditional declares the built-in strlen to return int,
and has done so at least since version 2.4.5. -- rms. */
extern int strlen(const char *);
# endif /* not __STDC__ */
#endif /* __GNUC__ */
#endif /* not __GNU_LIBRARY__ */
/* Handle permutation of arguments. */
/* Describe the part of ARGV that contains non-options that have
been skipped. `first_nonopt' is the index in ARGV of the first of them;
`last_nonopt' is the index after the last of them. */
static int first_nonopt;
static int last_nonopt;
#ifdef _LIBC
/* Stored original parameters.
XXX This is no good solution. We should rather copy the args so
that we can compare them later. But we must not use malloc(3). */
extern int __libc_argc;
extern char **__libc_argv;
/* Bash 2.0 gives us an environment variable containing flags
indicating ARGV elements that should not be considered arguments. */
# ifdef USE_NONOPTION_FLAGS
/* Defined in getopt_init.c */
extern char *__getopt_nonoption_flags;
static int nonoption_flags_max_len;
static int nonoption_flags_len;
# endif
# ifdef USE_NONOPTION_FLAGS
# define SWAP_FLAGS(ch1, ch2) \
if (nonoption_flags_len > 0) \
{ \
char __tmp = __getopt_nonoption_flags[ch1]; \
__getopt_nonoption_flags[ch1] = __getopt_nonoption_flags[ch2]; \
__getopt_nonoption_flags[ch2] = __tmp; \
}
# else
# define SWAP_FLAGS(ch1, ch2)
# endif
#else /* !_LIBC */
# define SWAP_FLAGS(ch1, ch2)
#endif /* _LIBC */
/* Exchange two adjacent subsequences of ARGV.
One subsequence is elements [first_nonopt,last_nonopt)
which contains all the non-options that have been skipped so far.
The other is elements [last_nonopt,optind), which contains all
the options processed since those non-options were skipped.
`first_nonopt' and `last_nonopt' are relocated so that they describe
the new indices of the non-options in ARGV after they are moved. */
#if defined __STDC__ && __STDC__
static void exchange(char **);
#endif
static void
exchange(argv)
char **argv;
{
int bottom = first_nonopt;
int middle = last_nonopt;
int top = optind;
char *tem;
/* Exchange the shorter segment with the far end of the longer segment.
That puts the shorter segment into the right place.
It leaves the longer segment in the right place overall,
but it consists of two parts that need to be swapped next. */
#if defined _LIBC && defined USE_NONOPTION_FLAGS
/* First make sure the handling of the `__getopt_nonoption_flags'
string can work normally. Our top argument must be in the range
of the string. */
if (nonoption_flags_len > 0 && top >= nonoption_flags_max_len)
{
/* We must extend the array. The user plays games with us and
presents new arguments. */
char *new_str = malloc(top + 1);
if (new_str == NULL)
nonoption_flags_len = nonoption_flags_max_len = 0;
else
{
memset(__mempcpy(new_str, __getopt_nonoption_flags,
nonoption_flags_max_len),
'\0', top + 1 - nonoption_flags_max_len);
nonoption_flags_max_len = top + 1;
__getopt_nonoption_flags = new_str;
}
}
#endif
while (top > middle && middle > bottom)
{
if (top - middle > middle - bottom)
{
/* Bottom segment is the short one. */
int len = middle - bottom;
register int i;
/* Swap it with the top part of the top segment. */
for (i = 0; i < len; i++)
{
tem = argv[bottom + i];
argv[bottom + i] = argv[top - (middle - bottom) + i];
argv[top - (middle - bottom) + i] = tem;
SWAP_FLAGS(bottom + i, top - (middle - bottom) + i);
}
/* Exclude the moved bottom segment from further swapping. */
top -= len;
}
else
{
/* Top segment is the short one. */
int len = top - middle;
register int i;
/* Swap it with the bottom part of the bottom segment. */
for (i = 0; i < len; i++)
{
tem = argv[bottom + i];
argv[bottom + i] = argv[middle + i];
argv[middle + i] = tem;
SWAP_FLAGS(bottom + i, middle + i);
}
/* Exclude the moved top segment from further swapping. */
bottom += len;
}
}
/* Update records for the slots the non-options now occupy. */
first_nonopt += (optind - last_nonopt);
last_nonopt = optind;
}
/* Initialize the internal data when the first call is made. */
#if defined __STDC__ && __STDC__
static const char *_getopt_initialize(int, char *const *, const char *);
#endif
static const char *
_getopt_initialize(argc, argv, optstring)
int argc;
char *const *argv;
const char *optstring;
{
/* Start processing options with ARGV-element 1 (since ARGV-element 0
is the program name); the sequence of previously skipped
non-option ARGV-elements is empty. */
first_nonopt = last_nonopt = optind;
nextchar = NULL;
posixly_correct = getenv("POSIXLY_CORRECT");
/* Determine how to handle the ordering of options and nonoptions. */
if (optstring[0] == '-')
{
ordering = RETURN_IN_ORDER;
++optstring;
}
else if (optstring[0] == '+')
{
ordering = REQUIRE_ORDER;
++optstring;
}
else if (posixly_correct != NULL)
ordering = REQUIRE_ORDER;
else
ordering = PERMUTE;
#if defined _LIBC && defined USE_NONOPTION_FLAGS
if (posixly_correct == NULL
&& argc == __libc_argc && argv == __libc_argv)
{
if (nonoption_flags_max_len == 0)
{
if (__getopt_nonoption_flags == NULL
|| __getopt_nonoption_flags[0] == '\0')
nonoption_flags_max_len = -1;
else
{
const char *orig_str = __getopt_nonoption_flags;
int len = nonoption_flags_max_len = strlen(orig_str);
if (nonoption_flags_max_len < argc)
nonoption_flags_max_len = argc;
__getopt_nonoption_flags =
(char *)malloc(nonoption_flags_max_len);
if (__getopt_nonoption_flags == NULL)
nonoption_flags_max_len = -1;
else
memset(__mempcpy(__getopt_nonoption_flags, orig_str, len),
'\0', nonoption_flags_max_len - len);
}
}
nonoption_flags_len = nonoption_flags_max_len;
}
else
nonoption_flags_len = 0;
#endif
return optstring;
}
/* Scan elements of ARGV (whose length is ARGC) for option characters
given in OPTSTRING.
If an element of ARGV starts with '-', and is not exactly "-" or "--",
then it is an option element. The characters of this element
(aside from the initial '-') are option characters. If `getopt'
is called repeatedly, it returns successively each of the option characters
from each of the option elements.
If `getopt' finds another option character, it returns that character,
updating `optind' and `nextchar' so that the next call to `getopt' can
resume the scan with the following option character or ARGV-element.
If there are no more option characters, `getopt' returns -1.
Then `optind' is the index in ARGV of the first ARGV-element
that is not an option. (The ARGV-elements have been permuted
so that those that are not options now come last.)
OPTSTRING is a string containing the legitimate option characters.
If an option character is seen that is not listed in OPTSTRING,
return '?' after printing an error message. If you set `opterr' to
zero, the error message is suppressed but we still return '?'.
If a char in OPTSTRING is followed by a colon, that means it wants an arg,
so the following text in the same ARGV-element, or the text of the following
ARGV-element, is returned in `optarg'. Two colons mean an option that
wants an optional arg; if there is text in the current ARGV-element,
it is returned in `optarg', otherwise `optarg' is set to zero.
If OPTSTRING starts with `-' or `+', it requests different methods of
handling the non-option ARGV-elements.
See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
Long-named options begin with `--' instead of `-'.
Their names may be abbreviated as long as the abbreviation is unique
or is an exact match for some defined option. If they have an
argument, it follows the option name in the same ARGV-element, separated
from the option name by a `=', or else the in next ARGV-element.
When `getopt' finds a long-named option, it returns 0 if that option's
`flag' field is nonzero, the value of the option's `val' field
if the `flag' field is zero.
The elements of ARGV aren't really const, because we permute them.
But we pretend they're const in the prototype to be compatible
with other systems.
LONGOPTS is a vector of `struct option' terminated by an
element containing a name which is zero.
LONGIND returns the index in LONGOPT of the long-named option found.
It is only valid when a long-named option has been found by the most
recent call.
If LONG_ONLY is nonzero, '-' as well as '--' can introduce
long-named options. */
int
_getopt_internal(argc, argv, optstring, longopts, longind, long_only)
int argc;
char *const *argv;
const char *optstring;
const struct option *longopts;
int *longind;
int long_only;
{
int print_errors = opterr;
if (optstring[0] == ':')
print_errors = 0;
if (argc < 1)
return -1;
optarg = NULL;
if (optind == 0 || !__getopt_initialized)
{
if (optind == 0)
optind = 1; /* Don't scan ARGV[0], the program name. */
optstring = _getopt_initialize(argc, argv, optstring);
__getopt_initialized = 1;
}
/* Test whether ARGV[optind] points to a non-option argument.
Either it does not have option syntax, or there is an environment flag
from the shell indicating it is not an option. The later information
is only used when the used in the GNU libc. */
#if defined _LIBC && defined USE_NONOPTION_FLAGS
# define NONOPTION_P (argv[optind][0] != '-' || argv[optind][1] == '\0' \
|| (optind < nonoption_flags_len \
&& __getopt_nonoption_flags[optind] == '1'))
#else
# define NONOPTION_P (argv[optind][0] != '-' || argv[optind][1] == '\0')
#endif
if (nextchar == NULL || *nextchar == '\0')
{
/* Advance to the next ARGV-element. */
/* Give FIRST_NONOPT & LAST_NONOPT rational values if OPTIND has been
moved back by the user (who may also have changed the arguments). */
if (last_nonopt > optind)
last_nonopt = optind;
if (first_nonopt > optind)
first_nonopt = optind;
if (ordering == PERMUTE)
{
/* If we have just processed some options following some non-options,
exchange them so that the options come first. */
if (first_nonopt != last_nonopt && last_nonopt != optind)
exchange((char **)argv);
else if (last_nonopt != optind)
first_nonopt = optind;
/* Skip any additional non-options
and extend the range of non-options previously skipped. */
while (optind < argc && NONOPTION_P)
optind++;
last_nonopt = optind;
}
/* The special ARGV-element `--' means premature end of options.
Skip it like a null option,
then exchange with previous non-options as if it were an option,
then skip everything else like a non-option. */
if (optind != argc && !strcmp(argv[optind], "--"))
{
optind++;
if (first_nonopt != last_nonopt && last_nonopt != optind)
exchange((char **)argv);
else if (first_nonopt == last_nonopt)
first_nonopt = optind;
last_nonopt = argc;
optind = argc;
}
/* If we have done all the ARGV-elements, stop the scan
and back over any non-options that we skipped and permuted. */
if (optind == argc)
{
/* Set the next-arg-index to point at the non-options
that we previously skipped, so the caller will digest them. */
if (first_nonopt != last_nonopt)
optind = first_nonopt;
return -1;
}
/* If we have come to a non-option and did not permute it,
either stop the scan or describe it to the caller and pass it by. */
if (NONOPTION_P)
{
if (ordering == REQUIRE_ORDER)
return -1;
optarg = argv[optind++];
return 1;
}
/* We have found another option-ARGV-element.
Skip the initial punctuation. */
nextchar = (argv[optind] + 1
+ (longopts != NULL && argv[optind][1] == '-'));
}
/* Decode the current option-ARGV-element. */
/* Check whether the ARGV-element is a long option.
If long_only and the ARGV-element has the form "-f", where f is
a valid short option, don't consider it an abbreviated form of
a long option that starts with f. Otherwise there would be no
way to give the -f short option.
On the other hand, if there's a long option "fubar" and
the ARGV-element is "-fu", do consider that an abbreviation of
the long option, just like "--fu", and not "-f" with arg "u".
This distinction seems to be the most useful approach. */
if (longopts != NULL
&& (argv[optind][1] == '-'
|| (long_only && (argv[optind][2] || !my_index(optstring, argv[optind][1])))))
{
char *nameend;
const struct option *p;
const struct option *pfound = NULL;
int exact = 0;
int ambig = 0;
int indfound = -1;
int option_index;
for (nameend = nextchar; *nameend && *nameend != '='; nameend++)
/* Do nothing. */;
/* Test all long options for either exact match
or abbreviated matches. */
for (p = longopts, option_index = 0; p->name; p++, option_index++)
if (!strncmp(p->name, nextchar, nameend - nextchar))
{
if ((unsigned int)(nameend - nextchar)
== (unsigned int)strlen(p->name))
{
/* Exact match found. */
pfound = p;
indfound = option_index;
exact = 1;
break;
}
else if (pfound == NULL)
{
/* First nonexact match found. */
pfound = p;
indfound = option_index;
}
else if (long_only
|| pfound->has_arg != p->has_arg
|| pfound->flag != p->flag
|| pfound->val != p->val)
/* Second or later nonexact match found. */
ambig = 1;
}
if (ambig && !exact)
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf, _("%s: option `%s' is ambiguous\n"),
argv[0], argv[optind]);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr, _("%s: option `%s' is ambiguous\n"),
argv[0], argv[optind]);
#endif
}
nextchar += strlen(nextchar);
optind++;
optopt = 0;
return '?';
}
if (pfound != NULL)
{
option_index = indfound;
optind++;
if (*nameend)
{
/* Don't test has_arg with >, because some C compilers don't
allow it to be used on enums. */
if (pfound->has_arg)
optarg = nameend + 1;
else
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
#endif
if (argv[optind - 1][1] == '-')
{
/* --option */
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("\
%s: option `--%s' doesn't allow an argument\n"),
argv[0], pfound->name);
#else
fprintf(stderr, _("\
%s: option `--%s' doesn't allow an argument\n"),
argv[0], pfound->name);
#endif
}
else
{
/* +option or -option */
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("\
%s: option `%c%s' doesn't allow an argument\n"),
argv[0], argv[optind - 1][0],
pfound->name);
#else
fprintf(stderr, _("\
%s: option `%c%s' doesn't allow an argument\n"),
argv[0], argv[optind - 1][0], pfound->name);
#endif
}
#if defined _LIBC && defined USE_IN_LIBIO
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#endif
}
nextchar += strlen(nextchar);
optopt = pfound->val;
return '?';
}
}
else if (pfound->has_arg == 1)
{
if (optind < argc)
optarg = argv[optind++];
else
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf,
_("%s: option `%s' requires an argument\n"),
argv[0], argv[optind - 1]);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr,
_("%s: option `%s' requires an argument\n"),
argv[0], argv[optind - 1]);
#endif
}
nextchar += strlen(nextchar);
optopt = pfound->val;
return optstring[0] == ':' ? ':' : '?';
}
}
nextchar += strlen(nextchar);
if (longind != NULL)
*longind = option_index;
if (pfound->flag)
{
*(pfound->flag) = pfound->val;
return 0;
}
return pfound->val;
}
/* Can't find it as a long option. If this is not getopt_long_only,
or the option starts with '--' or is not a valid short
option, then it's an error.
Otherwise interpret it as a short option. */
if (!long_only || argv[optind][1] == '-'
|| my_index(optstring, *nextchar) == NULL)
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
#endif
if (argv[optind][1] == '-')
{
/* --option */
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("%s: unrecognized option `--%s'\n"),
argv[0], nextchar);
#else
fprintf(stderr, _("%s: unrecognized option `--%s'\n"),
argv[0], nextchar);
#endif
}
else
{
/* +option or -option */
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("%s: unrecognized option `%c%s'\n"),
argv[0], argv[optind][0], nextchar);
#else
fprintf(stderr, _("%s: unrecognized option `%c%s'\n"),
argv[0], argv[optind][0], nextchar);
#endif
}
#if defined _LIBC && defined USE_IN_LIBIO
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#endif
}
nextchar = (char *) "";
optind++;
optopt = 0;
return '?';
}
}
/* Look at and handle the next short option-character. */
{
char c = *nextchar++;
char *temp = my_index(optstring, c);
/* Increment `optind' when we start to process its last character. */
if (*nextchar == '\0')
++optind;
if (temp == NULL || c == ':')
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
#endif
if (posixly_correct)
{
/* 1003.2 specifies the format of this message. */
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("%s: illegal option -- %c\n"),
argv[0], c);
#else
fprintf(stderr, _("%s: illegal option -- %c\n"), argv[0], c);
#endif
}
else
{
#if defined _LIBC && defined USE_IN_LIBIO
__asprintf(&buf, _("%s: invalid option -- %c\n"),
argv[0], c);
#else
fprintf(stderr, _("%s: invalid option -- %c\n"), argv[0], c);
#endif
}
#if defined _LIBC && defined USE_IN_LIBIO
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#endif
}
optopt = c;
return '?';
}
/* Convenience. Treat POSIX -W foo same as long option --foo */
if (temp[0] == 'W' && temp[1] == ';')
{
char *nameend;
const struct option *p;
const struct option *pfound = NULL;
int exact = 0;
int ambig = 0;
int indfound = 0;
int option_index;
/* This is an option that requires an argument. */
if (*nextchar != '\0')
{
optarg = nextchar;
/* If we end this ARGV-element by taking the rest as an arg,
we must advance to the next element now. */
optind++;
}
else if (optind == argc)
{
if (print_errors)
{
/* 1003.2 specifies the format of this message. */
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf, _("%s: option requires an argument -- %c\n"),
argv[0], c);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr, _("%s: option requires an argument -- %c\n"),
argv[0], c);
#endif
}
optopt = c;
if (optstring[0] == ':')
c = ':';
else
c = '?';
return c;
}
else
/* We already incremented `optind' once;
increment it again when taking next ARGV-elt as argument. */
optarg = argv[optind++];
/* optarg is now the argument, see if it's in the
table of longopts. */
for (nextchar = nameend = optarg; *nameend && *nameend != '='; nameend++)
/* Do nothing. */;
/* Test all long options for either exact match
or abbreviated matches. */
for (p = longopts, option_index = 0; p->name; p++, option_index++)
if (!strncmp(p->name, nextchar, nameend - nextchar))
{
if ((unsigned int)(nameend - nextchar) == strlen(p->name))
{
/* Exact match found. */
pfound = p;
indfound = option_index;
exact = 1;
break;
}
else if (pfound == NULL)
{
/* First nonexact match found. */
pfound = p;
indfound = option_index;
}
else
/* Second or later nonexact match found. */
ambig = 1;
}
if (ambig && !exact)
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf, _("%s: option `-W %s' is ambiguous\n"),
argv[0], argv[optind]);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr, _("%s: option `-W %s' is ambiguous\n"),
argv[0], argv[optind]);
#endif
}
nextchar += strlen(nextchar);
optind++;
return '?';
}
if (pfound != NULL)
{
option_index = indfound;
if (*nameend)
{
/* Don't test has_arg with >, because some C compilers don't
allow it to be used on enums. */
if (pfound->has_arg)
optarg = nameend + 1;
else
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf, _("\
%s: option `-W %s' doesn't allow an argument\n"),
argv[0], pfound->name);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr, _("\
%s: option `-W %s' doesn't allow an argument\n"),
argv[0], pfound->name);
#endif
}
nextchar += strlen(nextchar);
return '?';
}
}
else if (pfound->has_arg == 1)
{
if (optind < argc)
optarg = argv[optind++];
else
{
if (print_errors)
{
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf, _("\
%s: option `%s' requires an argument\n"),
argv[0], argv[optind - 1]);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr,
_("%s: option `%s' requires an argument\n"),
argv[0], argv[optind - 1]);
#endif
}
nextchar += strlen(nextchar);
return optstring[0] == ':' ? ':' : '?';
}
}
nextchar += strlen(nextchar);
if (longind != NULL)
*longind = option_index;
if (pfound->flag)
{
*(pfound->flag) = pfound->val;
return 0;
}
return pfound->val;
}
nextchar = NULL;
return 'W'; /* Let the application handle it. */
}
if (temp[1] == ':')
{
if (temp[2] == ':')
{
/* This is an option that accepts an argument optionally. */
if (*nextchar != '\0')
{
optarg = nextchar;
optind++;
}
else
optarg = NULL;
nextchar = NULL;
}
else
{
/* This is an option that requires an argument. */
if (*nextchar != '\0')
{
optarg = nextchar;
/* If we end this ARGV-element by taking the rest as an arg,
we must advance to the next element now. */
optind++;
}
else if (optind == argc)
{
if (print_errors)
{
/* 1003.2 specifies the format of this message. */
#if defined _LIBC && defined USE_IN_LIBIO
char *buf;
__asprintf(&buf,
_("%s: option requires an argument -- %c\n"),
argv[0], c);
if (_IO_fwide(stderr, 0) > 0)
__fwprintf(stderr, L"%s", buf);
else
fputs(buf, stderr);
free(buf);
#else
fprintf(stderr,
_("%s: option requires an argument -- %c\n"),
argv[0], c);
#endif
}
optopt = c;
if (optstring[0] == ':')
c = ':';
else
c = '?';
}
else
/* We already incremented `optind' once;
increment it again when taking next ARGV-elt as argument. */
optarg = argv[optind++];
nextchar = NULL;
}
}
return c;
}
}
int
getopt(argc, argv, optstring)
int argc;
char *const *argv;
const char *optstring;
{
return _getopt_internal(argc, argv, optstring,
(const struct option *) 0,
(int *)0,
0);
}
int
getopt_long(int argc, char *const *argv, const char *options,
const struct option *long_options, int *opt_index)
{
return _getopt_internal(argc, argv, options, long_options, opt_index, 0, 0);
}
int
getopt_long_only(int argc, char *const *argv, const char *options,
const struct option *long_options, int *opt_index)
{
return _getopt_internal(argc, argv, options, long_options, opt_index, 1, 0);
}
#endif /* Not ELIDE_CODE. */
#ifdef TEST
/* Compile with -DTEST to make an executable for use in testing
the above definition of `getopt'. */
int
main(argc, argv)
int argc;
char **argv;
{
int c;
int digit_optind = 0;
while (1)
{
int this_option_optind = optind ? optind : 1;
c = getopt(argc, argv, "abc:d:0123456789");
if (c == -1)
break;
switch (c)
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (digit_optind != 0 && digit_optind != this_option_optind)
printf("digits occur in two different argv-elements.\n");
digit_optind = this_option_optind;
printf("option %c\n", c);
break;
case 'a':
printf("option a\n");
break;
case 'b':
printf("option b\n");
break;
case 'c':
printf("option c with value `%s'\n", optarg);
break;
case '?':
break;
default:
printf("?? getopt returned character code 0%o ??\n", c);
}
}
if (optind < argc)
{
printf("non-option ARGV-elements: ");
while (optind < argc)
printf("%s ", argv[optind++]);
printf("\n");
}
exit(0);
}
#endif /* TEST */
