src/misc/mntent.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <mntent.h>
   4 #include <errno.h>
   5
   6 static char *internal_buf;
   7 static size_t internal_bufsize;
   8
   9 #define SENTINEL (char *)&internal_buf
  10
  11 FILE *setmntent(const char *name, const char *mode)
  12 {
  13         return fopen(name, mode);
  14 }
  15
  16 int endmntent(FILE *f)
  17 {
  18         if (f) fclose(f);
  19         return 1;
  20 }
  21
  22 struct mntent *getmntent_r(FILE *f, struct mntent *mnt, char *linebuf, int buflen)
  23 {
  24         int n[8], use_internal = (linebuf == SENTINEL);
  25         size_t len, i;
  26
  27         mnt->mnt_freq = 0;
  28         mnt->mnt_passno = 0;
  29
  30         do {
  31                 if (use_internal) {
  32                         getline(&internal_buf, &internal_bufsize, f);
  33                         linebuf = internal_buf;
  34                 } else {
  35                         fgets(linebuf, buflen, f);
  36                 }
  37                 if (feof(f) || ferror(f)) return 0;
  38                 if (!strchr(linebuf, '\n')) {
  39                         fscanf(f, "%*[^\n]%*[\n]");
  40                         errno = ERANGE;
  41                         return 0;
  42                 }
  43
  44                 len = strlen(linebuf);
  45                 for (i = 0; i < sizeof n / sizeof *n; i++) n[i] = len;
  46                 sscanf(linebuf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
  47                         n, n+1, n+2, n+3, n+4, n+5, n+6, n+7,
  48                         &mnt->mnt_freq, &mnt->mnt_passno);
  49         } while (linebuf[n[0]] == '#' || n[1]==len);
  50
  51         linebuf[n[1]] = 0;
  52         linebuf[n[3]] = 0;
  53         linebuf[n[5]] = 0;
  54         linebuf[n[7]] = 0;
  55
  56         mnt->mnt_fsname = linebuf+n[0];
  57         mnt->mnt_dir = linebuf+n[2];
  58         mnt->mnt_type = linebuf+n[4];
  59         mnt->mnt_opts = linebuf+n[6];
  60
  61         return mnt;
  62 }
  63
  64 struct mntent *getmntent(FILE *f)
  65 {
  66         static struct mntent mnt;
  67         return getmntent_r(f, &mnt, SENTINEL, 0);
  68 }
  69
  70 int addmntent(FILE *f, const struct mntent *mnt)
  71 {
  72         if (fseek(f, 0, SEEK_END)) return 1;
  73         return fprintf(f, "%s\t%s\t%s\t%s\t%d\t%d\n",
  74                 mnt->mnt_fsname, mnt->mnt_dir, mnt->mnt_type, mnt->mnt_opts,
  75                 mnt->mnt_freq, mnt->mnt_passno) < 0;
  76 }
  77
  78 char *hasmntopt(const struct mntent *mnt, const char *opt)
  79 {
  80         return strstr(mnt->mnt_opts, opt);
  81 }