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Simple c like regular expression. The regular expression is stored in a buffer, compiled and then used.
More examples of regular expression as well as other cpp examples are at: main page. Some of these cpp regular expression use boost library. I was not able to install the boost on my debian wheezy. For this example I need no installation for any package, to get it work well, on a lenny debian machine.

  1. #include <sys/types.h>
  2. #include <regex.h>
  3. #include <locale.h>
  4. #include <stdio.h>
  5. #include <string.h>
  6. #include <nl_types.h>
  7. #define SLENGTH 128
  12. int match(char *pattern, char *string)
  13. {
  14.   char message[SLENGTH];
  15.   char *start_search;
  16.   int error, msize, count;
  17.   regex_t preg;
  18.   regmatch_t pmatch;
  19.   
  20.   //REG_ICASE | REG_EXTENDED);
  21.   error = regcomp(&preg, pattern, REG_EXTENDED);
  22.   if (error) {
  23.     msize = regerror(error, &preg, message, SLENGTH);
  24.     printf("%s\n", message);
  25.     if (msize > SLENGTH)
  26.     printf("Additional text lost\n");
  27.     return 1;
  28.   }
  29.   error = regexec(&preg, string, 1, &pmatch, 0);
  30.   if (error == REG_NOMATCH) {
  31.     printf("No matches in string\n");
  32.     return 1;
  33.   } else if (error != 0) {
  34.     msize = regerror(error, &preg, message, SLENGTH);
  35.     printf("%s\n", message);
  36.     if (msize > SLENGTH)
  37.     printf("Additional text lost\n");
  38.     return 1;
  39.   };
  40.   count = 1;
  41.   start_search = string + pmatch.rm_eo;
  42.   while (error == 0) {
  43.     error =
  44.     regexec(&preg, start_search, 1, &pmatch, REG_NOTBOL);
  45.     start_search = start_search + pmatch.rm_eo;
  46.     count++;
  47.     printf("match at %d\n", pmatch.rm_eo);
  48.     //Print sub match
  49.     unsigned matchlen;
  50.     matchlen=pmatch.rm_eo - pmatch.rm_so;
  51.     char * submatch = new char[matchlen+1];
  52.     strncpy(submatch, &string[pmatch.rm_so], matchlen+1);
  53.     submatch[matchlen]='\0';
  54.     printf("%s\n", submatch);
  55.     delete[] submatch;
  56.   };
  57.   count--;
  58.   printf("There were %d matches\n", count);
  59.   regfree(&preg);
  60. }
  62. main()
  63. {
  64.   char patt[SLENGTH], strng[SLENGTH];
  65.   char *eol;
  66.   
  67.   (void)setlocale(LC_ALL, "");
  68.   
  69.   printf("Enter a regular expression:");
  70.   fgets(patt, SLENGTH, stdin);
  71.   if ((eol = strchr(patt, '\n')) != NULL)
  72.   *eol = '\0'; /* Replace newline with null */
  73.   else
  74.   return 1; /* Line entered too long */
  75.   printf("Enter string to compare\nString: ");
  76.   fgets(strng, SLENGTH, stdin);
  77.   if ((eol = strchr(strng, '\n')) != NULL)
  78.   *eol = '\0'; /* Replace newline with null */
  79.   else return 1; /* Line entered too long */
  80.   
  81.   match(patt, strng);
  82. }
  ...


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