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我想使用 getopt,但它行不通。
它给了我
gcc -g -Wall -std=c99 -ftrapv -O2 -Werror -Wshadow -Wundef -save-temps -Werror-implicit-function-declaration -c -o src/main.o src/main.c
src/main.c: In function ‘main’:
src/main.c:13:2: error: implicit declaration of function ‘getopt’ [-Werror=implicit-function-declaration]
src/main.c:23:14: error: ‘optarg’ undeclared (first use in this function)
src/main.c:23:14: note: each undeclared identifier is reported only once for each function it appears in
src/main.c:26:9: error: ‘optopt’ undeclared (first use in this function)
src/main.c:28:5: error: implicit declaration of function ‘isprint’ [-Werror=implicit-function-declaration]
src/main.c:36:5: error: implicit declaration of function ‘abort’ [-Werror=implicit-function-declaration]
src/main.c:36:5: error: incompatible implicit declaration of built-in function ‘abort’ [-Werror]
src/main.c:43:15: error: ‘optind’ undeclared (first use in this function)
cc1: all warnings being treated as errors
make: *** [src/main.o] Error 1
如果你想看,这里是源代码(几乎完全复制 getopt 联机帮助页)
#include <stdio.h>
#include <unistd.h> // getopt
#include "myfn.h"
int main(int argc, char *argv[])
{
int aflag = 0;
int bflag = 0;
char *cvalue = NULL;
int c;
while((c = getopt(argc, argv, "abc:")) != -1) {
switch(c) {
case 'a':
aflag = 1;
break;
case 'b':
bflag = 1;
break;
case 'c':
cvalue = optarg;
break;
case '?':
if (optopt == 'c')
fprintf (stderr, "Option -%c requires an argument.\n", optopt);
else if (isprint(optopt))
fprintf (stderr, "Unknown option `-%c'.\n", optopt);
else
fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt);
return 1;
default:
abort ();
}
}
printf ("aflag = %d, bflag = %d, cvalue = %s\n", aflag, bflag, cvalue);
for (int i = optind; i < argc; i++) {
printf ("Non-option argument %s\n", argv[i]);
}
return 0;
}
知道我做错了什么吗?
我在 Linux 上,所以我认为它应该像这样工作。
最佳答案
尝试删除 -std=c99
.这可以防止在 <features.h>
中定义 POSIX 宏。 ,这可以防止 <unistd.h>
来自包括 <getopt.h>
.或者自己包含 getopt.h。
关于c - Getopt 不包括在内?函数 ‘getopt’ 的隐式声明,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22575940/
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