Trancker log analyzer

tracker_log_analyzer.c

// gcc -Wall tracker_log_analyzer.c && ./a.out | sort | uniq -c | sort -nr > rank.txt

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<ctype.h>

#define BUF_SIZE (1024 * 64)
#define PREFIX "info_hash="

int main(int argc, char *argv[]) {
  char buf[BUF_SIZE], hex[64], *ps, *pe, ch;
  FILE *f = fopen("2096.log", "r");
  while (fgets(buf, BUF_SIZE, f) != NULL) {
    ps = strstr(buf, PREFIX);
    if (!ps) continue;
    for (pe = ps + strlen(PREFIX), ps = hex; *pe != ' ' && *pe != '&';) {
      ch = *pe++;

      switch (ch) {
      case '%':
        *ps++ = tolower(*pe++);
        *ps++ = tolower(*pe++);
        break;
      case '+':
        ch = ' ';
      default:
        snprintf(ps, 3, "%02x", ch);
        ps += 2;
      }
    }
    *ps = '\0';
    puts(hex);
  }

  return 0;
}