POSIX正则无法匹配中括号的问题

wrongway88_cu

有一个字符串是"[大家好]"，想提取出其中的"大家好"，用regcomp和regexec两个函数做的，pattern是这样写的
char pattern[] = "\[([^\]]+)\]";
char pattern[] = "\[([^\\]]+)\]";
char pattern[] = "\[([^\\\]]+)\]";
char pattern[] = "[([^]]+)]";
char pattern[] = "[([^\\\]]+)]";
以上均无法匹配，我该如何写呢？

程序代码如下：
#include <stdio.h>
#include <regex.h>
#include <string.h>

int main(int argc, char **argv) {
    regex_t re;
    regmatch_t subs[10];
    char errbuf[256];
    char matched[256];
    char pattern[] = "[([^]]+)]";
    char string[] = "[大家好]";
    int err, i;
    const size_t nmatch = 10;
    size_t len;

    err = regcomp (&re, pattern, REG_EXTENDED);
    if (err)
    {
        len = regerror (err, &re, errbuf, sizeof (errbuf));
        fprintf (stderr, "error: regcomp: %s\n", errbuf);
        exit (1);
    }

    printf ("Total has subexpression: %d\n", re.re_nsub);
    /* execute pattern match */
    err = regexec (&re, string, nmatch, subs, 0);
    if (err == REG_NOMATCH)
    {
        fprintf (stderr, "Sorry, no match ...\n");
        regfree (&re);
        exit (0);
    }
    else if (err)
    {
        len = regerror (err, &re, errbuf, sizeof (errbuf));
        fprintf (stderr, "error: regexec: %s\n", errbuf);
        exit (1);
    }


    /* if no REG_NOMATCH and no error, then pattern matched */
    printf ("\nOK, has matched ...\n\n");
    for (i = 0; i <= re.re_nsub; i++)
    {
        if (i == 0)
        {
        printf ("begin: %d, end: %d, ",subs.rm_so, subs.rm_eo);
        }
        else
        {
        printf ("subexpression %d begin: %d, end: %d, ", i, subs.rm_so, subs.rm_eo);
        }
        len = subs.rm_eo - subs.rm_so;
        memcpy(matched, string + subs.rm_so, len);
        matched[len] = '\0';
        printf("match: %s\n", matched);
    }

    regfree(&re);
    exit(0);


}

wrongway88_cu

自己顶一下

没本

1. 
   
2. 
   
3. $ cat reg.c
   
4. #include <stdio.h>
   
5. #include <regex.h>
   
6. #include <string.h>
   
7. 
   
8. int main(int argc, char **argv) {
   
9.     regex_t re;
   
10.     regmatch_t subs[10];
    
11.     char errbuf[256];
    
12.     char matched[256];
    
13.     char pattern[] = "\\[(.*)]";
    
14.     char string[] = "[大家好]";
    
15.     int err, i;
    
16.     const size_t nmatch = 10;
    
17.     size_t len;
    
18. 
    
19.     err = regcomp (&re, pattern, REG_EXTENDED);
    
20.     if (err)
    
21.     {
    
22.         len = regerror (err, &re, errbuf, sizeof (errbuf));
    
23.         fprintf (stderr, "error: regcomp: %s\n", errbuf);
    
24.         exit (1);
    
25.     }
    
26. 
    
27.     printf ("Total has subexpression: %d\n", re.re_nsub);
    
28.     /* execute pattern match */
    
29.     err = regexec (&re, string, nmatch, subs, 0);
    
30.     if (err == REG_NOMATCH)
    
31.     {
    
32.         fprintf (stderr, "Sorry, no match ...\n");
    
33.         regfree (&re);
    
34.         exit (0);
    
35.     }
    
36.     else if (err)
    
37.     {
    
38.         len = regerror (err, &re, errbuf, sizeof (errbuf));
    
39.         fprintf (stderr, "error: regexec: %s\n", errbuf);
    
40.         exit (1);
    
41.     }
    
42. 
    
43. 
    
44.     /* if no REG_NOMATCH and no error, then pattern matched */
    
45.     printf ("\nOK, has matched ...\n\n");
    
46.     for (i = 0; i <= re.re_nsub; i++)
    
47.     {
    
48.         if (i == 0)
    
49.         {
    
50.         printf ("begin: %d, end: %d, ",subs[i].rm_so, subs[i].rm_eo);
    
51.         }
    
52.         else
    
53.         {
    
54.         printf ("subexpression %d begin: %d, end: %d, ", i, subs[i].rm_so, subs[i].rm_eo);
    
55.         }
    
56.         len = subs[i].rm_eo - subs[i].rm_so;
    
57.         memcpy(matched, string + subs[i].rm_so, len);
    
58.         matched[len] = '\0';
    
59.         printf("match: %s\n", matched);
    
60.     }
    
61. 
    
62.     regfree(&re);
    
63.     exit(0);
    
64. 
    
65. 
    
66. }
    
67. 
    
68. $ gcc -o reg reg.c
    
69. reg.c: In function ‘main’:
    
70. reg.c:21:9: warning: incompatible implicit declaration of built-in function ‘exit’
    
71. reg.c:24:5: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘size_t’
    
72. reg.c:31:9: warning: incompatible implicit declaration of built-in function ‘exit’
    
73. reg.c:37:9: warning: incompatible implicit declaration of built-in function ‘exit’
    
74. reg.c:60:5: warning: incompatible implicit declaration of built-in function ‘exit’
    
75. $ ./reg
    
76. Total has subexpression: 1
    
77. 
    
78. OK, has matched ...
    
79. 
    
80. begin: 0, end: 11, match: [大家好]
    
81. subexpression 1 begin: 1, end: 10, match: 大家好
    
82. $
    

复制代码

wrongway88_cu

为什么是 \\[ 呢？

wrongway88_cu

我用PHP写的规则是 \[([^]]+)] ，为什么到了C就不好使了呢？