/* Utilities for reading/writing fstab, mtab, etc. Copyright (C) 1995-2000, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <alloca.h> #include <mntent.h> #include <stdio.h> #include <stdio_ext.h> #include <string.h> #include <sys/types.h> #ifdef USE_IN_LIBIO # define flockfile(s) _IO_flockfile (s) # define funlockfile(s) _IO_funlockfile (s) #endif /* Prepare to begin reading and/or writing mount table entries from the beginning of FILE. MODE is as for `fopen'. */ FILE * __setmntent (const char *file, const char *mode) { FILE *result = fopen (file, mode); if (result != NULL) /* We do the locking ourselves. */ __fsetlocking (result, FSETLOCKING_BYCALLER); return result; } weak_alias (__setmntent, setmntent) /* Close a stream opened with `setmntent'. */ int __endmntent (FILE *stream) { if (stream) /* SunOS 4.x allows for NULL stream */ fclose (stream); return 1; /* SunOS 4.x says to always return 1 */ } weak_alias (__endmntent, endmntent) /* Since the values in a line are separated by spaces, a name cannot contain a space. Therefore some programs encode spaces in names by the strings "\040". We undo the encoding when reading an entry. The decoding happens in place. */ static char * decode_name (char *buf) { char *rp = buf; char *wp = buf; do if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '4' && rp[3] == '0') { /* \040 is a SPACE. */ *wp++ = ' '; rp += 3; } else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '2') { /* \012 is a TAB. */ *wp++ = '\t'; rp += 3; } else if (rp[0] == '\\' && rp[1] == '\\') { /* We have to escape \\ to be able to represent all characters. */ *wp++ = '\\'; rp += 1; } else *wp++ = *rp; while (*rp++ != '\0'); return buf; } /* Read one mount table entry from STREAM. Returns a pointer to storage reused on the next call, or null for EOF or error (use feof/ferror to check). */ struct mntent * __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz) { char *cp; char *head; flockfile (stream); do { char *end_ptr; if (fgets_unlocked (buffer, bufsiz, stream) == NULL) { funlockfile (stream); return NULL; } end_ptr = strchr (buffer, '\n'); if (end_ptr != NULL) /* chop newline */ *end_ptr = '\0'; else { /* Not the whole line was read. Do it now but forget it. */ char tmp[1024]; while (fgets_unlocked (tmp, sizeof tmp, stream) != NULL) if (strchr (tmp, '\n') != NULL) break; } head = buffer + strspn (buffer, " \t"); /* skip empty lines and comment lines: */ } while (head[0] == '\0' || head[0] == '#'); cp = __strsep (&head, " \t"); mp->mnt_fsname = cp != NULL ? decode_name (cp) : (char *) ""; if (head) head += strspn (head, " \t"); cp = __strsep (&head, " \t"); mp->mnt_dir = cp != NULL ? decode_name (cp) : (char *) ""; if (head) head += strspn (head, " \t"); cp = __strsep (&head, " \t"); mp->mnt_type = cp != NULL ? decode_name (cp) : (char *) ""; if (head) head += strspn (head, " \t"); cp = __strsep (&head, " \t"); mp->mnt_opts = cp != NULL ? decode_name (cp) : (char *) ""; switch (head ? sscanf (head, " %d %d ", &mp->mnt_freq, &mp->mnt_passno) : 0) { case 0: mp->mnt_freq = 0; case 1: mp->mnt_passno = 0; case 2: break; } funlockfile (stream); return mp; } weak_alias (__getmntent_r, getmntent_r) /* We have to use an encoding for names if they contain spaces or tabs. To be able to represent all characters we also have to escape the backslash itself. This "function" must be a macro since we use `alloca'. */ #define encode_name(name) \ do { \ const char *rp = name; \ \ while (*rp != '\0') \ if (*rp == ' ' || *rp == '\t' || *rp == '\\') \ break; \ else \ ++rp; \ \ if (*rp != '\0') \ { \ /* In the worst case the length of the string can increase to \ founr times the current length. */ \ char *wp; \ \ rp = name; \ name = wp = (char *) alloca (strlen (name) * 4 + 1); \ \ do \ if (*rp == ' ') \ { \ *wp++ = '\\'; \ *wp++ = '0'; \ *wp++ = '4'; \ *wp++ = '0'; \ } \ else if (*rp == '\t') \ { \ *wp++ = '\\'; \ *wp++ = '0'; \ *wp++ = '1'; \ *wp++ = '2'; \ } \ else if (*rp == '\\') \ { \ *wp++ = '\\'; \ *wp++ = '\\'; \ } \ else \ *wp++ = *rp; \ while (*rp++ != '\0'); \ } \ } while (0) /* Write the mount table entry described by MNT to STREAM. Return zero on success, nonzero on failure. */ int __addmntent (FILE *stream, const struct mntent *mnt) { struct mntent mntcopy = *mnt; if (fseek (stream, 0, SEEK_END)) return 1; /* Encode spaces and tabs in the names. */ encode_name (mntcopy.mnt_fsname); encode_name (mntcopy.mnt_dir); encode_name (mntcopy.mnt_type); encode_name (mntcopy.mnt_opts); return (fprintf (stream, "%s %s %s %s %d %d\n", mntcopy.mnt_fsname, mntcopy.mnt_dir, mntcopy.mnt_type, mntcopy.mnt_opts, mntcopy.mnt_freq, mntcopy.mnt_passno) < 0 ? 1 : 0); } weak_alias (__addmntent, addmntent) /* Search MNT->mnt_opts for an option matching OPT. Returns the address of the substring, or null if none found. */ char * __hasmntopt (const struct mntent *mnt, const char *opt) { const size_t optlen = strlen (opt); char *rest = mnt->mnt_opts, *p; while ((p = strstr (rest, opt)) != NULL) { if (p == rest || (p[-1] == ',' && (p[optlen] == '\0' || p[optlen] == '=' || p[optlen] == ','))) return p; rest = strchr (rest, ','); if (rest == NULL) break; ++rest; } return NULL; } weak_alias (__hasmntopt, hasmntopt)