diff options
Diffstat (limited to 'REORG.TODO/misc/mntent_r.c')
| -rw-r--r-- | REORG.TODO/misc/mntent_r.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/REORG.TODO/misc/mntent_r.c b/REORG.TODO/misc/mntent_r.c new file mode 100644 index 0000000000..30f55212be --- /dev/null +++ b/REORG.TODO/misc/mntent_r.c @@ -0,0 +1,296 @@ +/* Utilities for reading/writing fstab, mtab, etc. + Copyright (C) 1995-2017 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, see + <http://www.gnu.org/licenses/>. */ + +#include <alloca.h> +#include <mntent.h> +#include <stdio.h> +#include <stdio_ext.h> +#include <string.h> +#include <sys/types.h> + +#define flockfile(s) _IO_flockfile (s) +#define funlockfile(s) _IO_funlockfile (s) + +#undef __setmntent +#undef __endmntent +#undef __getmntent_r + +/* 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) +{ + /* Extend the mode parameter with "c" to disable cancellation in the + I/O functions and "e" to set FD_CLOEXEC. */ + size_t modelen = strlen (mode); + char newmode[modelen + 3]; + memcpy (mempcpy (newmode, mode, modelen), "ce", 3); + FILE *result = fopen (file, newmode); + + if (result != NULL) + /* We do the locking ourselves. */ + __fsetlocking (result, FSETLOCKING_BYCALLER); + + return result; +} +libc_hidden_def (__setmntent) +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 */ +} +libc_hidden_def (__endmntent) +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] == '1') + { + /* \011 is a TAB. */ + *wp++ = '\t'; + rp += 3; + } + else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '2') + { + /* \012 is a NEWLINE. */ + *wp++ = '\n'; + rp += 3; + } + else if (rp[0] == '\\' && rp[1] == '\\') + { + /* We have to escape \\ to be able to represent all characters. */ + *wp++ = '\\'; + rp += 1; + } + else if (rp[0] == '\\' && rp[1] == '1' && rp[2] == '3' && rp[3] == '4') + { + /* \134 is also \\. */ + *wp++ = '\\'; + rp += 3; + } + 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 */ + { + /* Do not walk past the start of buffer if it's all whitespace. */ + while (end_ptr != buffer + && (end_ptr[-1] == ' ' || end_ptr[-1] == '\t')) + end_ptr--; + *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; +} +libc_hidden_def (__getmntent_r) +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 == '\n' || *rp == '\\') \ + break; \ + else \ + ++rp; \ + \ + if (*rp != '\0') \ + { \ + /* In the worst case the length of the string can increase to \ + four 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++ = '1'; \ + } \ + else if (*rp == '\n') \ + { \ + *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 + || fflush (stream) != 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 (p, ','); + if (rest == NULL) + break; + ++rest; + } + + return NULL; +} +weak_alias (__hasmntopt, hasmntopt) |