regexp.c

#include <stdio.h>
#include <regex.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>


char * stringarr[] = {
  "817 (Calendar) S 246 112 0 0 -1 4194624 6534 0 83 0 139 8 0 0 38 18 11 0 22117 61526016 5437 4294967295 32768 34809 3204114848 3204111656 1074820320 0 0 69634 1073777896 4294967295 0 0 17 0 0 0 0 0 0",
  "246 ((Nuwa)) S 112 112 0 0 -1 4194560 8245 0 33 0 108 18 0 0 21 1 13 0 1080 54116352 3415 4294967295 32768 34809 3204114848 3204111296 1074820320 0 0 69634 36072 4294967295 0 0 17 0 0 0 0 0 0",
  "910 ((Preallocated a) S 246 112 0 0 -1 4194368 2715 0 0 0 5 5 0 0 38 18 10 0 27168 58302464 3049 4294967295 32768 34809 3204114848 3204111656 1074820320 0 0 69634 36072 4294967295 0 0 17 0 0 0 0 0 0",
  "910 (I have a really long process name) S 246 112 0 0 -1 4194368 2715 0 0 0 5 5 0 0 38 18 10 0 27168 58302464 3049 4294967295 32768 34809 3204114848 3204111656 1074820320 0 0 69634 36072 4294967295 0 0 17 0 0 0 0 0 0",
  "910 (I (ahem) am pareny) S 246 112 0 0 -1 4194368 2715 0 0 0 5 5 0 0 38 18 10 0 27168 58302464 3049 4294967295 32768 34809 3204114848 3204111656 1074820320 0 0 69634 36072 4294967295 0 0 17 0 0 0 0 0 0"
};

int main(void) {
  static char * pattern =
    "^"        // beginning of string
    "([0-9]+) "    // pid
    "(\\(.*\\)) "// comm
    "[A-Z] "  // state
    "([0-9]+) "   // ppid       #include <sys/types.h>
    "[0-9]+ "  // pgrp
    "[0-9]+ "  // session
    "[0-9]+ "  // tty_nr
    "-?[0-9]+ "  // tpgid
    "[0-9]+ "  // flags
    "[0-9]+ "  // minflt (%lu)
    "[0-9]+ "  // cminflt (%lu)
    "[0-9]+ "  // majflt (%lu)
    "[0-9]+ "  // cmajflt (%lu)
    "[0-9]+ "  // utime (%lu)
    "[0-9]+ "  // stime (%ld)
    "[0-9]+ "  // cutime (%ld)
    "[0-9]+ "  // cstime (%ld)
    "[0-9]+ "  // priority (%ld)
    "([0-9]+)"; // niceness
  regex_t    preg;
  int i, rc;

  if (0 != (rc = regcomp(&preg, pattern, REG_EXTENDED))) {
    printf("regcomp() failed, returning nonzero (%d)\n", rc);
    exit(EXIT_FAILURE);
  }

  for (i = 0 ; i < sizeof(stringarr) / sizeof(stringarr[0]) ; i++) {
    char name[32];
    long int nice;
    int pid2, ppid;

    size_t     nmatch = 5;
    regmatch_t pmatch[5];
    int rc;

    if (0 != (rc = regexec(&preg, stringarr[i], nmatch, pmatch, 0))) {
      printf("Failed to match '%s' with '%s',returning %d.\n",
             stringarr[i], pattern, rc);
    } else {
      pid2 = (int) strtol(stringarr[i] + pmatch[1].rm_so, (char **) NULL, 10);
      strncpy(name, stringarr[i] + pmatch[2].rm_so, pmatch[2].rm_eo - pmatch[2].rm_so);
      name[pmatch[2].rm_eo - pmatch[2].rm_so] = 0;
      ppid = (int) strtol(stringarr[i] + pmatch[3].rm_so, (char **) NULL, 10);
      nice = (int) strtol(stringarr[i] + pmatch[4].rm_so, (char **) NULL, 10);

      printf("MATCHED %d/%d (%ld): %s\n", pid2, ppid, nice, name);
    }
  }

  regfree(&preg);

  return 0;
}