tools/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 date[1000];
  14 static char name[1000];
  15 static char email[1000];
  16 static char subject[1000];
  17
  18 static char *sanity_check(char *name, char *email)
  19 {
  20         int len = strlen(name);
  21         if (len < 3 || len > 60)
  22                 return email;
  23         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  24                 return email;
  25         return name;
  26 }
  27
  28 static int handle_from(char *line)
  29 {
  30         char *at = strchr(line, '@');
  31         char *dst;
  32
  33         if (!at)
  34                 return 0;
  35
  36         /*
  37          * If we already have one email, don't take any confusing lines
  38          */
  39         if (*email && strchr(at+1, '@'))
  40                 return 0;
  41
  42         while (at > line) {
  43                 char c = at[-1];
  44                 if (isspace(c) || c == '<')
  45                         break;
  46                 at--;
  47         }
  48         dst = email;
  49         for (;;) {
  50                 unsigned char c = *at;
  51                 if (!c || c == '>' || isspace(c))
  52                         break;
  53                 *at++ = ' ';
  54                 *dst++ = c;
  55         }
  56         *dst++ = 0;
  57
  58         at = line + strlen(line);
  59         while (at > line) {
  60                 unsigned char c = *--at;
  61                 if (isalnum(c))
  62                         break;
  63                 *at = 0;
  64         }
  65
  66         at = line;
  67         for (;;) {
  68                 unsigned char c = *at;
  69                 if (!c)
  70                         break;
  71                 if (isalnum(c))
  72                         break;
  73                 at++;
  74         }
  75
  76         at = sanity_check(at, email);
  77
  78         strcpy(name, at);
  79         return 1;
  80 }
  81
  82 static void handle_date(char *line)
  83 {
  84         strcpy(date, line);
  85 }
  86
  87 static void handle_subject(char *line)
  88 {
  89         strcpy(subject, line);
  90 }
  91
  92 static void check_line(char *line, int len)
  93 {
  94         if (!memcmp(line, "From:", 5) && isspace(line[5]))
  95                 handle_from(line+6);
  96         else if (!memcmp(line, "Date:", 5) && isspace(line[5]))
  97                 handle_date(line+6);
  98         else if (!memcmp(line, "Subject:", 8) && isspace(line[8]))
  99                 handle_subject(line+9);
 100 }
 101
 102 static char * cleanup_subject(char *subject)
 103 {
 104         for (;;) {
 105                 char *p;
 106                 int len, remove;
 107                 switch (*subject) {
 108                 case 'r': case 'R':
 109                         if (!memcmp("e:", subject+1, 2)) {
 110                                 subject +=3;
 111                                 continue;
 112                         }
 113                         break;
 114                 case ' ': case '\t': case ':':
 115                         subject++;
 116                         continue;
 117
 118                 case '[':
 119                         p = strchr(subject, ']');
 120                         if (!p) {
 121                                 subject++;
 122                                 continue;
 123                         }
 124                         len = strlen(p);
 125                         remove = p - subject;
 126                         if (remove <= len *2) {
 127                                 subject = p+1;
 128                                 continue;
 129                         }
 130                         break;
 131                 }
 132                 return subject;
 133         }
 134 }
 135
 136 static void cleanup_space(char *buf)
 137 {
 138         unsigned char c;
 139         while ((c = *buf) != 0) {
 140                 buf++;
 141                 if (isspace(c)) {
 142                         buf[-1] = ' ';
 143                         c = *buf;
 144                         while (isspace(c)) {
 145                                 int len = strlen(buf);
 146                                 memmove(buf, buf+1, len);
 147                                 c = *buf;
 148                         }
 149                 }
 150         }
 151 }
 152
 153 static void handle_rest(void)
 154 {
 155         char *sub = cleanup_subject(subject);
 156         cleanup_space(name);
 157         cleanup_space(date);
 158         cleanup_space(email);
 159         cleanup_space(sub);
 160         printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n", name, email, sub, date);
 161         FILE *out = cmitmsg;
 162
 163         do {
 164                 if (!memcmp("diff -", line, 6) ||
 165                     !memcmp("---", line, 3) ||
 166                     !memcmp("Index: ", line, 7))
 167                         out = patchfile;
 168
 169                 fputs(line, out);
 170         } while (fgets(line, sizeof(line), stdin) != NULL);
 171
 172         if (out == cmitmsg) {
 173                 fprintf(stderr, "No patch found\n");
 174                 exit(1);
 175         }
 176
 177         fclose(cmitmsg);
 178         fclose(patchfile);
 179 }
 180
 181 static int eatspace(char *line)
 182 {
 183         int len = strlen(line);
 184         while (len > 0 && isspace(line[len-1]))
 185                 line[--len] = 0;
 186         return len;
 187 }
 188
 189 static void handle_body(void)
 190 {
 191         int has_from = 0;
 192         int has_date = 0;
 193
 194         /* First lines of body can have From: and Date: */
 195         while (fgets(line, sizeof(line), stdin) != NULL) {
 196                 int len = eatspace(line);
 197                 if (!len)
 198                         continue;
 199                 if (!memcmp("From:", line, 5) && isspace(line[5])) {
 200                         if (!has_from && handle_from(line+6)) {
 201                                 has_from = 1;
 202                                 continue;
 203                         }
 204                 }
 205                 if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 206                         if (!has_date) {
 207                                 handle_date(line+6);
 208                                 has_date = 1;
 209                                 continue;
 210                         }
 211                 }
 212                 line[len] = '\n';
 213                 handle_rest();
 214                 break;
 215         }
 216 }
 217
 218 static int read_one_header_line(char *line, int sz, FILE *in)
 219 {
 220         int ofs = 0;
 221         while (ofs < sz) {
 222                 int peek, len;
 223                 if (fgets(line + ofs, sz - ofs, in) == NULL)
 224                         return ofs;
 225                 len = eatspace(line + ofs);
 226                 if (len == 0)
 227                         return ofs;
 228                 peek = fgetc(in); ungetc(peek, in);
 229                 if (peek == ' ' || peek == '\t') {
 230                         /* Yuck, 2822 header "folding" */
 231                         ofs += len;
 232                         continue;
 233                 }
 234                 return ofs + len;
 235         }
 236         return ofs;
 237 }
 238
 239 static void usage(void)
 240 {
 241         fprintf(stderr, "mailinfo msg-file patch-file < email\n");
 242         exit(1);
 243 }
 244
 245 int main(int argc, char ** argv)
 246 {
 247         if (argc != 3)
 248                 usage();
 249         cmitmsg = fopen(argv[1], "w");
 250         if (!cmitmsg) {
 251                 perror(argv[1]);
 252                 exit(1);
 253         }
 254         patchfile = fopen(argv[2], "w");
 255         if (!patchfile) {
 256                 perror(argv[2]);
 257                 exit(1);
 258         }
 259         while (1) {
 260                 int len = read_one_header_line(line, sizeof(line), stdin);
 261                 if (!len) {
 262                         handle_body();
 263                         break;
 264                 }
 265                 check_line(line, len);
 266         }
 267         return 0;
 268 }