asciisearch

Small utility for ascii string search (including control characters).
git clone git://git.stephanospavlou.info/asciisearch.git
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asciisearch.c (3342B)

      1 /*
      2 **    asciisearch.c
      3 **    Author: Stephanos Pavlou
      4 **    Small utility for ascii string search (including control characters). 
      5 */
      6 
      7 #include <stdio.h>
      8 #include <stdlib.h>
      9 #include <string.h>
     10 
     11 #define VERSION "0.1.0"
     12 #define ESC_CHAR '+'
     13 
     14 unsigned char *encode_pattern(char *pattern, int *len);
     15 int search_for_pattern(unsigned char *pattern, int len, char *file_name);
     16 
     17 char *usage_msg =
     18 "asciisearch-"VERSION"\n"
     19 "Usage: asciisearch [pattern] [file]\n";
     20 
     21 char *ctrl_char_code[] = {
     22     "^A", "^B", "^C", "^D", "^E", "^F",
     23     "^G", "^H", "^I", "^J", "^K", "^L",
     24     "^M", "^N", "^O", "^P", "^Q", "^R",
     25     "^S", "^T", "^U", "^V", "^W", "^X",
     26     "^Y", "^Z", "^@", "^[", "^\\", "^]",
     27     "^^", "^_", "^?"
     28 };
     29 
     30 unsigned char ctrl_char[] = {
     31     0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
     32     0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
     33     0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12,
     34     0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
     35     0x19, 0x1a, 0x00, 0x1b, 0x1c, 0x1d,
     36     0x1e, 0x1f, 0x7f
     37 };
     38 
     39 int
     40 main(int argc, char **argv) {
     41     if (argc != 3) {
     42         printf("%s", usage_msg);
     43         return 0;
     44     }
     45     
     46     int *len= malloc(sizeof(int));
     47     unsigned char *pattern = encode_pattern(argv[1], len);
     48     printf("encoded pattern: ");
     49     for (int i = 0; i < *len; i++) {
     50         fputc(pattern[i], stdout);
     51     }
     52     printf("\n");
     53     return search_for_pattern(pattern, *len, argv[2]);
     54 }
     55 
     56 unsigned char *
     57 encode_pattern(char *pattern, int *len) {
     58     *len = 0;
     59     unsigned char *result = NULL;
     60     for (int i = 0; i < strlen(pattern); i++) {
     61         if (pattern[i] == '^') {
     62             for (int j = 0; j < 33; j++) {
     63                 if (strstr(pattern + i, ctrl_char_code[j])
     64                         == pattern + i) {
     65                     result = realloc(result,
     66                         sizeof(unsigned char) * ++(*len));
     67                     result[*len - 1] = ctrl_char[j];
     68                     i++;
     69                     break;
     70                 }
     71             } 
     72         } else if (i + 1 < strlen(pattern) && 
     73             (pattern[i] == ESC_CHAR && pattern[i + 1] == '^')) {
     74             for (int j = 0; j < 33; j++) {
     75                 if (i + 1 < strlen(pattern) && 
     76                     (strstr(pattern + i, ctrl_char_code[j])
     77                         == pattern + (i + 1))) {
     78                     result = realloc(result,
     79                         sizeof(unsigned char) * ++(*len));
     80                     result[*len - 1] = pattern[i + 1];
     81                     i++;
     82                     break;
     83                 }
     84             }
     85         } else {
     86             result = realloc(result,
     87                 sizeof(unsigned char) * ++(*len));
     88             result[*len - 1] = pattern[i];
     89         }
     90     }
     91 
     92     return result;
     93 }
     94 
     95 int
     96 search_for_pattern(unsigned char *pattern, int len, 
     97         char *file_name) {
     98     int ret = 1;
     99     FILE *fp = fopen(file_name, "r");
    100     if (fp == NULL) {
    101         return ret;
    102     }
    103 
    104     int c;
    105     while ((c = fgetc(fp)) != EOF) {
    106         if (c == (int)pattern[0]) {
    107             int found = 1;
    108             for (int i = 1; i < len && (c = fgetc(fp)) != EOF; i++) {
    109                 if ((int)pattern[i] != c) {
    110                     found = 0;
    111                     break;
    112                 } 
    113             }
    114             if (c != EOF && found == 1) {
    115                 ret = 0;
    116                 break;
    117             }
    118         }
    119     }
    120     
    121     fclose(fp);
    122     return ret;
    123 }