mailinfo.c

   1 /*
   2  * Another stupid program, this one parsing the headers of an
   3  * email to figure out authorship and subject
   4  */
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <ctype.h>
   9
  10 static FILE *cmitmsg, *patchfile;
  11
  12 static char line[1000];
  13 static char name[1000];
  14 static char email[1000];
  15 static char subject[1000];
  16
  17 static char *sanity_check(char *name, char *email)
  18 {
  19         int len = strlen(name);
  20         if (len < 3 || len > 60)
  21                 return email;
  22         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  23                 return email;
  24         return name;
  25 }
  26
  27 static int handle_from(char *line)
  28 {
  29         char *at = strchr(line, '@');
  30         char *dst;
  31
  32         if (!at)
  33                 return 0;
  34
  35         /*
  36          * If we already have one email, don't take any confusing lines
  37          */
  38         if (*email && strchr(at+1, '@'))
  39                 return 0;
  40
  41         while (at > line) {
  42                 char c = at[-1];
  43                 if (isspace(c) || c == '<')
  44                         break;
  45                 at--;
  46         }
  47         dst = email;
  48         for (;;) {
  49                 unsigned char c = *at;
  50                 if (!c || c == '>' || isspace(c))
  51                         break;
  52                 *at++ = ' ';
  53                 *dst++ = c;
  54         }
  55         *dst++ = 0;
  56
  57         at = line + strlen(line);
  58         while (at > line) {
  59                 unsigned char c = *--at;
  60                 if (isalnum(c))
  61                         break;
  62                 *at = 0;
  63         }
  64
  65         at = line;
  66         for (;;) {
  67                 unsigned char c = *at;
  68                 if (!c)
  69                         break;
  70                 if (isalnum(c))
  71                         break;
  72                 at++;
  73         }
  74
  75         at = sanity_check(at, email);
  76
  77         strcpy(name, at);
  78         return 1;
  79 }
  80
  81 static void handle_subject(char *line)
  82 {
  83         strcpy(subject, line);
  84 }
  85
  86 static void add_subject_line(char *line)
  87 {
  88         while (isspace(*line))
  89                 line++;
  90         *--line = ' ';
  91         strcat(subject, line);
  92 }
  93
  94 static void check_line(char *line, int len)
  95 {
  96         static int cont = -1;
  97         if (!memcmp(line, "From:", 5) && isspace(line[5])) {
  98                 handle_from(line+6);
  99                 cont = 0;
 100                 return;
 101         }
 102         if (!memcmp(line, "Subject:", 8) && isspace(line[8])) {
 103                 handle_subject(line+9);
 104                 cont = 1;
 105                 return;
 106         }
 107         if (isspace(*line)) {
 108                 switch (cont) {
 109                 case 0:
 110                         fprintf(stderr, "I don't do 'From:' line continuations\n");
 111                         break;
 112                 case 1:
 113                         add_subject_line(line);
 114                         return;
 115                 default:
 116                         break;
 117                 }
 118         }
 119         cont = -1;
 120 }
 121
 122 static char * cleanup_subject(char *subject)
 123 {
 124         for (;;) {
 125                 char *p;
 126                 int len, remove;
 127                 switch (*subject) {
 128                 case 'r': case 'R':
 129                         if (!memcmp("e:", subject+1, 2)) {
 130                                 subject +=3;
 131                                 continue;
 132                         }
 133                         break;
 134                 case ' ': case '\t': case ':':
 135                         subject++;
 136                         continue;
 137
 138                 case '[':
 139                         p = strchr(subject, ']');
 140                         if (!p) {
 141                                 subject++;
 142                                 continue;
 143                         }
 144                         len = strlen(p);
 145                         remove = p - subject;
 146                         if (remove <= len *2) {
 147                                 subject = p+1;
 148                                 continue;
 149                         }
 150                         break;
 151                 }
 152                 return subject;
 153         }
 154 }
 155
 156 static void cleanup_space(char *buf)
 157 {
 158         unsigned char c;
 159         while ((c = *buf) != 0) {
 160                 buf++;
 161                 if (isspace(c)) {
 162                         buf[-1] = ' ';
 163                         c = *buf;
 164                         while (isspace(c)) {
 165                                 int len = strlen(buf);
 166                                 memmove(buf, buf+1, len);
 167                                 c = *buf;
 168                         }
 169                 }
 170         }
 171 }
 172
 173 /*
 174  * Hacky hacky. This depends not only on -p1, but on
 175  * filenames not having some special characters in them,
 176  * like tilde.
 177  */
 178 static void show_filename(char *line)
 179 {
 180         int len;
 181         char *name = strchr(line, '/');
 182
 183         if (!name || !isspace(*line))
 184                 return;
 185         name++;
 186         len = 0;
 187         for (;;) {
 188                 unsigned char c = name[len];
 189                 switch (c) {
 190                 default:
 191                         len++;
 192                         continue;
 193
 194                 case 0: case ' ':
 195                 case '\t': case '\n':
 196                         break;
 197
 198                 case '~':
 199                         break;
 200                 }
 201                 break;
 202         }
 203         /* remove ".orig" from the end - common patch behaviour */
 204         if (len > 5 && !memcmp(name+len-5, ".orig", 5))
 205                 len -=5;
 206         if (!len)
 207                 return;
 208         printf("filename: %.*s\n", len, name);
 209 }
 210
 211 static void handle_rest(void)
 212 {
 213         char *sub = cleanup_subject(subject);
 214         cleanup_space(name);
 215         cleanup_space(email);
 216         cleanup_space(sub);
 217         printf("Author: %s\nEmail: %s\nSubject: %s\n\n", name, email, sub);
 218         FILE *out = cmitmsg;
 219
 220         do {
 221                 /* Track filename information from the patch.. */
 222                 if (!memcmp("---", line, 3)) {
 223                         out = patchfile;
 224                         show_filename(line+3);
 225                 }
 226
 227                 if (!memcmp("+++", line, 3))
 228                         show_filename(line+3);
 229
 230                 fputs(line, out);
 231         } while (fgets(line, sizeof(line), stdin) != NULL);
 232
 233         if (out == cmitmsg) {
 234                 fprintf(stderr, "No patch found\n");
 235                 exit(1);
 236         }
 237
 238         fclose(cmitmsg);
 239         fclose(patchfile);
 240 }
 241
 242 static int eatspace(char *line)
 243 {
 244         int len = strlen(line);
 245         while (len > 0 && isspace(line[len-1]))
 246                 line[--len] = 0;
 247         return len;
 248 }
 249
 250 static void handle_body(void)
 251 {
 252         int has_from = 0;
 253
 254         /* First line of body can be a From: */
 255         while (fgets(line, sizeof(line), stdin) != NULL) {
 256                 int len = eatspace(line);
 257                 if (!len)
 258                         continue;
 259                 if (!memcmp("From:", line, 5) && isspace(line[5])) {
 260                         if (!has_from && handle_from(line+6)) {
 261                                 has_from = 1;
 262                                 continue;
 263                         }
 264                 }
 265                 line[len] = '\n';
 266                 handle_rest();
 267                 break;
 268         }
 269 }
 270
 271 static void usage(void)
 272 {
 273         fprintf(stderr, "mailinfo msg-file path-file < email\n");
 274         exit(1);
 275 }
 276
 277 int main(int argc, char ** argv)
 278 {
 279         if (argc != 3)
 280                 usage();
 281         cmitmsg = fopen(argv[1], "w");
 282         if (!cmitmsg) {
 283                 perror(argv[1]);
 284                 exit(1);
 285         }
 286         patchfile = fopen(argv[2], "w");
 287         if (!patchfile) {
 288                 perror(argv[2]);
 289                 exit(1);
 290         }
 291         while (fgets(line, sizeof(line), stdin) != NULL) {
 292                 int len = eatspace(line);
 293                 if (!len) {
 294                         handle_body();
 295                         break;
 296                 }
 297                 check_line(line, len);
 298         }
 299         return 0;
 300 }