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