mbox.c

   1 #include <ctype.h>
   2 #include <errno.h>
   3 #include <fcntl.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <time.h>
   7 #include <unistd.h>
   8 #include <utime.h>
   9 #include <sys/types.h>
  10 #include <sys/stat.h>
  11 #include "mbox.h"
  12 #include "util.h"
  13
  14 #define INCSIZE         (1 << 22)
  15
  16 static void set_atime(char *filename)
  17 {
  18         struct stat st;
  19         struct utimbuf times;
  20         stat(filename, &st);
  21         times.actime = time(NULL);
  22         times.modtime = st.st_mtime;
  23         utime(filename, &times);
  24 }
  25
  26 static char *mail_start(char *r)
  27 {
  28         char *s = r;
  29         char *t;
  30         while (*s) {
  31                 if (!strncmp("From ", s, 5) && (s == r || *(s - 1) == '\n'))
  32                         break;
  33                 t = strchr(s + 1, 'F');
  34                 s = t ? t : strchr(s, '\0');
  35         }
  36         return s;
  37 }
  38
  39 static char *mail_hdrs(struct mail *mail, char *s)
  40 {
  41         static char stat[] = "Status:";
  42         char *r;
  43         while (s && *s && *s != '\r' && *s != '\n') {
  44                 if (isalpha(*s) && mail->nhdrs < MAXHDRS)
  45                         mail->hdrs[mail->nhdrs++] = s;
  46                 if (!strncmp(stat, s, sizeof(stat) - 1))
  47                         mail->stat_hdr = s;
  48                 if ((r = strchr(s + 1, '\n')))
  49                         s = r + 1;
  50                 else
  51                         s = strchr(s + 1, '\0');
  52         }
  53         mail->hdrs[mail->nhdrs] = s;
  54         return s;
  55 }
  56
  57 static int startswith(char *s, char *r)
  58 {
  59         while (*r) {
  60                 int c1 = *s++;
  61                 int c2 = *r++;
  62                 if (tolower(c1) != tolower(c2))
  63                         return 0;
  64         }
  65         return 1;
  66 }
  67
  68 char *mail_hdr(struct mail *mail, char *hdr)
  69 {
  70         int i;
  71         for (i = 1; i < mail->nhdrs; i++)
  72                 if (startswith(mail->hdrs[i], hdr))
  73                         return mail->hdrs[i];
  74         return NULL;
  75 }
  76
  77 int hdr_len(char *hdr)
  78 {
  79         char *s = hdr;
  80         while (*s) {
  81                 char *r = strchr(s, '\n');
  82                 if (!r)
  83                         return strchr(s, '\0') - hdr;
  84                 s = r + 1;
  85                 if (!isspace(*s))
  86                         return s - hdr;
  87         }
  88         return 0;
  89 }
  90
  91 static void mail_stat(struct mail *mail)
  92 {
  93         if (mail->stat_hdr) {
  94                 char *s = mail->stat_hdr + strlen("Status:");
  95                 while (*s && *s != '\r' && *s != '\n') {
  96                         switch (*s++) {
  97                         case 'O':
  98                                 mail->stat |= STAT_OLD;
  99                                 break;
 100                         case 'N':
 101                                 mail->stat |= STAT_NEW;
 102                                 break;
 103                         case 'R':
 104                                 mail->stat |= STAT_READ;
 105                                 break;
 106                         }
 107                 }
 108                 mail->orig_stat = mail->stat;
 109         } else {
 110                 mail->stat = STAT_NEW;
 111         }
 112 }
 113
 114 char *mail_read(struct mail *mail, char *s)
 115 {
 116         char *end;
 117         mail->head = s;
 118         mail->body = mail_hdrs(mail, s);
 119         end = mail_start(mail->body);
 120         mail->len = end - mail->head;
 121         mail->body_len = end - mail->body;
 122         mail_stat(mail);
 123         return end;
 124 }
 125
 126 static void read_mails(struct mbox *mbox, char *s)
 127 {
 128         while (s && *s)
 129                 s = mail_read(&mbox->mails[mbox->n++], s);
 130 }
 131
 132 int mbox_inc(struct mbox *mbox)
 133 {
 134         int fd = open(mbox->path, O_RDONLY);
 135         int old_n = mbox->n;
 136         int old_len = mbox->len;
 137         int len = file_size(fd);
 138         if (fd == -1)
 139                 return 0;
 140         if (!mbox->mbox) {
 141                 mbox->size = len + INCSIZE + 1;
 142                 mbox->mbox = malloc(mbox->size);
 143         }
 144         if (len > mbox->size - 1)
 145                 return -1;
 146         if (mbox->len)
 147                 lseek(fd, mbox->len, SEEK_SET);
 148         mbox->len += xread(fd, mbox->mbox + mbox->len, len);
 149         mbox->mbox[mbox->len] = '\0';
 150         close(fd);
 151         set_atime(mbox->path);
 152         if (old_len < mbox->len)
 153                 read_mails(mbox, mbox->mbox + old_len);
 154         return mbox->n - old_n;
 155 }
 156
 157 struct mbox *mbox_alloc(char *filename)
 158 {
 159         struct mbox *mbox;
 160         mbox = malloc(sizeof(*mbox));
 161         memset(mbox, 0, sizeof(*mbox));
 162         strcpy(mbox->path, filename);
 163         mbox_inc(mbox);
 164         return mbox;
 165 }
 166
 167 void mbox_free(struct mbox *mbox)
 168 {
 169         free(mbox->mbox);
 170         free(mbox);
 171 }
 172
 173 int mail_head(struct mail *mail, char *buf, int buf_len,
 174                 char **hdrs, int n)
 175 {
 176         int i, j;
 177         char *s = buf;
 178         char *dead = s + buf_len;
 179         for (i = 0; i < n; i++) {
 180                 char *pat = hdrs[i];
 181                 for (j = 0; j < mail->nhdrs; j++) {
 182                         char *hdr = mail->hdrs[j];
 183                         if (startswith(hdr, pat)) {
 184                                 int hdr_len = mail->hdrs[j + 1] - hdr;
 185                                 if (s + hdr_len > dead)
 186                                         hdr_len = dead - s;
 187                                 memcpy(s, hdr, hdr_len);
 188                                 s += hdr_len;
 189                                 break;
 190                         }
 191                 }
 192         }
 193         *s = '\0';
 194         return s - buf;
 195 }
 196
 197 static int mail_changed(struct mail *mail)
 198 {
 199         return mail->orig_stat != mail->stat;
 200 }
 201
 202 void mail_write(struct mail *mail, int fd)
 203 {
 204         char stat[32] = "Status: ";
 205         char *s = strchr(stat, '\0');
 206         if (mail->stat & STAT_READ)
 207                 *s++ = 'R';
 208         if (mail->stat & STAT_OLD)
 209                 *s++ = 'O';
 210         if (mail->stat & STAT_NEW)
 211                 *s++ = 'N';
 212         *s++ = '\n';
 213         if (!mail_changed(mail)) {
 214                 xwrite(fd, mail->head, mail->len);
 215         } else {
 216                 char *hdr_beg = mail->body;
 217                 char *hdr_end = mail->body;
 218                 if (mail->stat_hdr) {
 219                         char *nl = strchr(mail->stat_hdr, '\n');
 220                         hdr_beg = mail->stat_hdr;
 221                         hdr_end = nl ? nl + 1 : mail->body;
 222                 }
 223                 xwrite(fd, mail->head, hdr_beg - mail->head);
 224                 xwrite(fd, stat, s - stat);
 225                 if (hdr_end)
 226                         xwrite(fd, hdr_end, mail->head + mail->len - hdr_end);
 227         }
 228 }
 229
 230 static int mbox_changed(struct mbox *mbox)
 231 {
 232         int i;
 233         for (i = 0; i < mbox->n; i++)
 234                 if (mail_changed(&mbox->mails[i]))
 235                         return 1;
 236         return 0;
 237 }
 238
 239 int mbox_write(struct mbox *mbox)
 240 {
 241         int fd;
 242         int i = 0;
 243         if (mbox_inc(mbox) == -1)
 244                 return -1;
 245         if (!mbox_changed(mbox))
 246                 return 0;
 247         fd = open(mbox->path, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
 248         while (i < mbox->n) {
 249                 char *beg = mbox->mails[i].head;
 250                 char *end = mbox->mbox + mbox->len;
 251                 while (i < mbox->n && !mail_changed(&mbox->mails[i]))
 252                         i++;
 253                 if (i < mbox->n)
 254                         end = mbox->mails[i].head;
 255                 xwrite(fd, beg, end - beg);
 256                 if (i < mbox->n && !(mbox->mails[i].stat & STAT_DEL))
 257                         mail_write(&mbox->mails[i], fd);
 258                 i++;
 259         }
 260         close(fd);
 261         return 0;
 262 }