pedecabra.c

   1 #include <stdlib.h>
   2 #include <unistd.h>
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <stdbool.h>
   6 #include <string.h>
   7 #include <libgen.h>
   8 #include <assert.h>
   9 #include <regex.h>
  10
  11 #include <magic.h>
  12
  13 /* Print Magic Error */
  14 #define PME {
  15
  16 /* very stupid aproach, but very simple :) */
  17 struct association_s {
  18     const char *filetype; /* filetype of the file */
  19     const char *viewapp;  /* path to the view program */
  20     const char *editapp;  /* path to the edit program */
  21 };
  22
  23 #include "config.h"
  24
  25 int entry_count = sizeof(associations)/sizeof(struct association_s);
  26
  27 /* determine <file> filetype
  28  *
  29  * if successfull <filetype> must be freed later by the user
  30  * returns true if successfull, false otherwise
  31  */
  32
  33 bool getfiletype(char *file, char **filetype)
  34 {
  35     assert (file != NULL);
  36
  37     magic_t mc; //magic_cookie
  38     char *magictype;
  39     int magictypelen;
  40     int stat;
  41
  42     stat = access(file, F_OK);
  43     if (stat == -1) {
  44         perror("AH");
  45         return false;
  46     }
  47
  48     mc = magic_open(MAGIC_NONE);
  49     if (mc == NULL) {
  50         perror("AH");
  51         return false;
  52     }
  53
  54     stat = magic_load(mc, NULL);
  55     if (stat == -1) {
  56         fprintf(stderr, "AH: %s", magic_error(mc));
  57         return false;
  58     }
  59
  60     magictype = magic_file(mc, file);
  61     if (magictype == NULL) {
  62         fprintf(stderr, "AH: %s", magic_error(mc));
  63         return false;
  64     }
  65     //printf("Magic says: %s\n\n", magictype);
  66
  67     /* "convert" (or copy) magic result to something local to close magic */
  68     magictypelen = strlen(magictype);
  69     (*filetype) = (char *)malloc(magictypelen+1);
  70     if (*filetype == NULL) {
  71         perror("AH");
  72         return false;
  73     }
  74     strncpy(*filetype, magictype, magictypelen+1);
  75
  76     /* no more magic */
  77     magic_close(mc);
  78
  79     return true;
  80 }
  81
  82 /* match <filetype> against local database
  83  *
  84  * <index> gets the index of the found entry, if successfull
  85  * returns true if entry was found, false otherwise
  86  */
  87 bool match(char *filetype, int *index)
  88 {
  89     assert(filetype != NULL);
  90     assert(index != NULL);
  91
  92     bool found;
  93     int r;
  94     regex_t preg;
  95
  96     /* this is a nasty piece of code. need to beautify!!! */
  97     for(r=0, found=false; (r < entry_count) && (found == false); ++r) {
  98         if (regcomp(&preg, associations[r].filetype, REG_EXTENDED | REG_NOSUB) != 0) {
  99             fprintf(stderr, "Unable to compile regex %s.\n", associations[r].filetype);
 100             return false;
 101         }
 102                 /* true on substring match. to match whole string prepend with '^' and append '$'. */
 103         if (regexec(&preg, filetype, 0, 0, 0) == 0) {
 104             found = true;
 105         }
 106     }
 107     --r;
 108     regfree(&preg);
 109
 110     *index = r;
 111     return found;
 112 }
 113
 114 void main (int argc, char *argv[])
 115 {
 116     bool stat;
 117     char *file;
 118     char *filetype;
 119     int index;
 120     char *newargv[3];
 121
 122     if (argc != 3) {
 123         fprintf(stderr, "%s: Incorrect arguments.\n", argv[0]);
 124         fprintf(stdout, "Usage: %s v|e <file>\n", argv[0]);
 125         fprintf(stdout, "\t v: opens file with application registered to view\n");
 126         fprintf(stdout, "\t e: opens file with application registered to edit\n");
 127         exit(EXIT_FAILURE);
 128     }
 129
 130     file = argv[2];
 131
 132     stat = getfiletype(file, &filetype);
 133     if (stat == false) {
 134         fprintf(stderr, "Could not determine %s type.\n", file);
 135         exit(EXIT_FAILURE);
 136     }
 137
 138     stat = match(filetype, &index);
 139     if (stat == false) {
 140         fprintf(stderr, "Type '%s' not configured.\nAdd it to associations "\
 141                 "array in config.h and recompile.\n", filetype);
 142         exit(EXIT_FAILURE);
 143     }
 144
 145     free(filetype);
 146
 147     switch (*argv[1]) {
 148         case 'e':
 149             newargv[0] = associations[index].editapp;
 150             newargv[1] = file;
 151             newargv[2] = (char *)NULL;
 152             stat = execv(associations[index].editapp, newargv);
 153             perror("AH");
 154             break;
 155         case 'v':
 156             newargv[0] = associations[index].viewapp;
 157             newargv[1] = file;
 158             newargv[2] = (char *)NULL;
 159             stat = execv(associations[index].viewapp, newargv);
 160             perror("AH");
 161             break;
 162         default:
 163             fprintf(stderr, "No application associated with the action %s for\
 164                     file %s.\n", argv[1], file);
 165             break;
 166     }
 167
 168     exit(EXIT_FAILURE);
 169 }