uidl.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include "uidl.h"
   9
  10 struct uidl {
  11         char *txt;
  12         int fd;
  13         char *prev;     /* the previous matched position */
  14 };
  15
  16 static int file_size(int fd)
  17 {
  18         struct stat st;
  19         fstat(fd, &st);
  20         return st.st_size;
  21 }
  22
  23 static int xread(int fd, char *buf, int len)
  24 {
  25         int nr = 0;
  26         while (nr < len) {
  27                 int cr = read(fd, buf + nr, len - nr);
  28                 if (cr == -1)
  29                         break;
  30                 nr += cr;
  31         }
  32         return nr;
  33 }
  34
  35 struct uidl *uidl_read(char *filename)
  36 {
  37         struct uidl *uidl = malloc(sizeof(*uidl));
  38         int len;
  39         memset(uidl, 0, sizeof(*uidl));
  40         uidl->fd = open(filename, O_RDWR | O_CREAT, 0600);
  41         len = file_size(uidl->fd);
  42         lseek(uidl->fd, 0, SEEK_SET);
  43         uidl->txt = malloc(len + 1);
  44         xread(uidl->fd, uidl->txt, len);
  45         uidl->txt[len] = '\0';
  46         lseek(uidl->fd, 0, SEEK_END);
  47         return uidl;
  48 }
  49
  50 static char *find_str(char *s, char *id)
  51 {
  52         int len = strlen(id);
  53         while (s && *s) {
  54                 if (!strncmp(s, id, len) && s[len] == '\n')
  55                         return s;
  56                 s = strchr(s, '\n');
  57                 s = s ? s + 1 : s;
  58         }
  59         return NULL;
  60 }
  61
  62 int uidl_find(struct uidl *uidl, char *id)
  63 {
  64         if (uidl->prev)
  65                 uidl->prev = find_str(uidl->prev, id);
  66         if (!uidl->prev)
  67                 uidl->prev = find_str(uidl->txt, id);
  68         return uidl->prev != NULL;
  69 }
  70
  71 void uidl_add(struct uidl *uidl, char *id)
  72 {
  73         char kw[256];
  74         snprintf(kw, sizeof(kw), "%s\n", id);
  75         write(uidl->fd, kw, strlen(kw));
  76 }
  77
  78 void uidl_save(struct uidl *uidl)
  79 {
  80         close(uidl->fd);
  81         free(uidl->txt);
  82         free(uidl);
  83 }