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 int keep_subject = 0;
  13 static char line[1000];
  14 static char date[1000];
  15 static char name[1000];
  16 static char email[1000];
  17 static char subject[1000];
  18
  19 static char *sanity_check(char *name, char *email)
  20 {
  21         int len = strlen(name);
  22         if (len < 3 || len > 60)
  23                 return email;
  24         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  25                 return email;
  26         return name;
  27 }
  28
  29 static int handle_from(char *line)
  30 {
  31         char *at = strchr(line, '@');
  32         char *dst;
  33
  34         if (!at)
  35                 return 0;
  36
  37         /*
  38          * If we already have one email, don't take any confusing lines
  39          */
  40         if (*email && strchr(at+1, '@'))
  41                 return 0;
  42
  43         while (at > line) {
  44                 char c = at[-1];
  45                 if (isspace(c) || c == '<')
  46                         break;
  47                 at--;
  48         }
  49         dst = email;
  50         for (;;) {
  51                 unsigned char c = *at;
  52                 if (!c || c == '>' || isspace(c))
  53                         break;
  54                 *at++ = ' ';
  55                 *dst++ = c;
  56         }
  57         *dst++ = 0;
  58
  59         at = line + strlen(line);
  60         while (at > line) {
  61                 unsigned char c = *--at;
  62                 if (isalnum(c))
  63                         break;
  64                 *at = 0;
  65         }
  66
  67         at = line;
  68         for (;;) {
  69                 unsigned char c = *at;
  70                 if (!c)
  71                         break;
  72                 if (isalnum(c))
  73                         break;
  74                 at++;
  75         }
  76
  77         at = sanity_check(at, email);
  78
  79         strcpy(name, at);
  80         return 1;
  81 }
  82
  83 static void handle_date(char *line)
  84 {
  85         strcpy(date, line);
  86 }
  87
  88 static void handle_subject(char *line)
  89 {
  90         strcpy(subject, line);
  91 }
  92
  93 static void check_line(char *line, int len)
  94 {
  95         if (!memcmp(line, "From:", 5) && isspace(line[5]))
  96                 handle_from(line+6);
  97         else if (!memcmp(line, "Date:", 5) && isspace(line[5]))
  98                 handle_date(line+6);
  99         else if (!memcmp(line, "Subject:", 8) && isspace(line[8]))
 100                 handle_subject(line+9);
 101 }
 102
 103 static char * cleanup_subject(char *subject)
 104 {
 105         if (keep_subject)
 106                 return subject;
 107         for (;;) {
 108                 char *p;
 109                 int len, remove;
 110                 switch (*subject) {
 111                 case 'r': case 'R':
 112                         if (!memcmp("e:", subject+1, 2)) {
 113                                 subject +=3;
 114                                 continue;
 115                         }
 116                         break;
 117                 case ' ': case '\t': case ':':
 118                         subject++;
 119                         continue;
 120
 121                 case '[':
 122                         p = strchr(subject, ']');
 123                         if (!p) {
 124                                 subject++;
 125                                 continue;
 126                         }
 127                         len = strlen(p);
 128                         remove = p - subject;
 129                         if (remove <= len *2) {
 130                                 subject = p+1;
 131                                 continue;
 132                         }
 133                         break;
 134                 }
 135                 return subject;
 136         }
 137 }
 138
 139 static void cleanup_space(char *buf)
 140 {
 141         unsigned char c;
 142         while ((c = *buf) != 0) {
 143                 buf++;
 144                 if (isspace(c)) {
 145                         buf[-1] = ' ';
 146                         c = *buf;
 147                         while (isspace(c)) {
 148                                 int len = strlen(buf);
 149                                 memmove(buf, buf+1, len);
 150                                 c = *buf;
 151                         }
 152                 }
 153         }
 154 }
 155
 156 static void handle_rest(void)
 157 {
 158         FILE *out = cmitmsg;
 159         char *sub = cleanup_subject(subject);
 160         cleanup_space(name);
 161         cleanup_space(date);
 162         cleanup_space(email);
 163         cleanup_space(sub);
 164         printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n", name, email, sub, date);
 165
 166         do {
 167                 if (!memcmp("diff -", line, 6) ||
 168                     !memcmp("---", line, 3) ||
 169                     !memcmp("Index: ", line, 7))
 170                         out = patchfile;
 171
 172                 fputs(line, out);
 173         } while (fgets(line, sizeof(line), stdin) != NULL);
 174
 175         if (out == cmitmsg) {
 176                 fprintf(stderr, "No patch found\n");
 177                 exit(1);
 178         }
 179
 180         fclose(cmitmsg);
 181         fclose(patchfile);
 182 }
 183
 184 static int eatspace(char *line)
 185 {
 186         int len = strlen(line);
 187         while (len > 0 && isspace(line[len-1]))
 188                 line[--len] = 0;
 189         return len;
 190 }
 191
 192 static void handle_body(void)
 193 {
 194         int has_from = 0;
 195         int has_date = 0;
 196
 197         /* First lines of body can have From: and Date: */
 198         while (fgets(line, sizeof(line), stdin) != NULL) {
 199                 int len = eatspace(line);
 200                 if (!len)
 201                         continue;
 202                 if (!memcmp("From:", line, 5) && isspace(line[5])) {
 203                         if (!has_from && handle_from(line+6)) {
 204                                 has_from = 1;
 205                                 continue;
 206                         }
 207                 }
 208                 if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 209                         if (!has_date) {
 210                                 handle_date(line+6);
 211                                 has_date = 1;
 212                                 continue;
 213                         }
 214                 }
 215                 line[len] = '\n';
 216                 handle_rest();
 217                 break;
 218         }
 219 }
 220
 221 static int read_one_header_line(char *line, int sz, FILE *in)
 222 {
 223         int ofs = 0;
 224         while (ofs < sz) {
 225                 int peek, len;
 226                 if (fgets(line + ofs, sz - ofs, in) == NULL)
 227                         return ofs;
 228                 len = eatspace(line + ofs);
 229                 if (len == 0)
 230                         return ofs;
 231                 peek = fgetc(in); ungetc(peek, in);
 232                 if (peek == ' ' || peek == '\t') {
 233                         /* Yuck, 2822 header "folding" */
 234                         ofs += len;
 235                         continue;
 236                 }
 237                 return ofs + len;
 238         }
 239         return ofs;
 240 }
 241
 242 static void usage(void)
 243 {
 244         fprintf(stderr, "mailinfo msg-file patch-file < email\n");
 245         exit(1);
 246 }
 247
 248 static const char mailinfo_usage[] =
 249 "git-mailinfo [-k] msg patch <mail >info";
 250 int main(int argc, char ** argv)
 251 {
 252         while (1 < argc && argv[1][0] == '-') {
 253                 if (!strcmp(argv[1], "-k"))
 254                         keep_subject = 1;
 255                 else {
 256                         fprintf(stderr, "usage: %s\n", mailinfo_usage);
 257                         exit(1);
 258                 }
 259                 argc--; argv++;
 260         }
 261
 262         if (argc != 3)
 263                 usage();
 264         cmitmsg = fopen(argv[1], "w");
 265         if (!cmitmsg) {
 266                 perror(argv[1]);
 267                 exit(1);
 268         }
 269         patchfile = fopen(argv[2], "w");
 270         if (!patchfile) {
 271                 perror(argv[2]);
 272                 exit(1);
 273         }
 274         while (1) {
 275                 int len = read_one_header_line(line, sizeof(line), stdin);
 276                 if (!len) {
 277                         handle_body();
 278                         break;
 279                 }
 280                 check_line(line, len);
 281         }
 282         return 0;
 283 }