/* movemail foo bar -- move file foo to file bar,
   locking file foo the way /bin/mail respects.
   Copyright (C) 1986, 1992, 1993, 1994, 1996 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Emacs 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Important notice: defining MAIL_USE_FLOCK or MAIL_USE_LOCKF *will
   cause loss of mail* if you do it on a system that does not normally
   use flock as its way of interlocking access to inbox files.  The
   setting of MAIL_USE_FLOCK and MAIL_USE_LOCKF *must agree* with the
   system's own conventions.  It is not a choice that is up to you.

   So, if your system uses lock files rather than flock, then the only way
   you can get proper operation is to enable movemail to write lockfiles there.
   This means you must either give that directory access modes
   that permit everyone to write lockfiles in it, or you must make movemail
   a setuid or setgid program.  */

/*
 * Modified January, 1986 by Michael R. Gretzinger (Project Athena)
 *
 * Added POP (Post Office Protocol) service.  When compiled -DMAIL_USE_POP
 * movemail will accept input filename arguments of the form
 * "po:username".  This will cause movemail to open a connection to
 * a pop server running on $MAILHOST (environment variable).  Movemail
 * must be setuid to root in order to work with POP.
 * 
 * New module: popmail.c
 * Modified routines:
 *	main - added code within #ifdef MAIL_USE_POP; added setuid (getuid ())
 *		after POP code. 
 * New routines in movemail.c:
 *	get_errmsg - return pointer to system error message
 *
 * Modified August, 1993 by Jonathan Kamens (OpenVision Technologies)
 *
 * Move all of the POP code into a separate file, "pop.c".
 * Use strerror instead of get_errmsg.
 *
 */

#define NO_SHORTNAMES   /* Tell config not to load remap.h */
#include <../src/config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <stdio.h>
#include <errno.h>
#include "../src/syswait.h"
#include "../src/systime.h"
#include <stdlib.h>
#include <string.h>
#include "getopt.h"
#ifdef MAIL_USE_POP
#include "pop.h"
#include "../src/regex.h"
#endif

extern char *optarg;
extern int optind, opterr;

#ifndef HAVE_STRERROR
char * strerror (int errnum);
#endif /* HAVE_STRERROR */

#ifdef MSDOS
#undef access
#endif /* MSDOS */

#ifndef DIRECTORY_SEP
#define DIRECTORY_SEP '/'
#endif
#ifndef IS_DIRECTORY_SEP
#define IS_DIRECTORY_SEP(_c_) ((_c_) == DIRECTORY_SEP)
#endif

#ifdef WINDOWSNT
#undef access
#undef unlink
#define fork() 0
#define sys_wait(var) (*(var) = 0)
/* Unfortunately, Samba doesn't seem to properly lock Unix files even
   though the locking call succeeds (and indeed blocks local access from
   other NT programs).  If you have direct file access using an NFS
   client or something other than Samba, the locking call might work
   properly - make sure it does before you enable this! */
#define DISABLE_DIRECT_ACCESS
#include <io.h>
#endif /* WINDOWSNT */

#if defined (HAVE_UNISTD_H) || defined (USG)
#include <unistd.h>
#endif /* unistd.h */
#ifndef F_OK
#define F_OK 0
#define X_OK 1
#define W_OK 2
#define R_OK 4
#endif /* No F_OK */

#if defined (HAVE_FCNTL_H) || defined (USG)
#include <fcntl.h>
#endif /* fcntl.h */

#if defined (XENIX) || defined (WINDOWSNT)
#include <sys/locking.h>
#endif

#ifdef MAIL_USE_LOCKF
#define MAIL_USE_SYSTEM_LOCK
#endif

#ifdef MAIL_USE_FLOCK
#define MAIL_USE_SYSTEM_LOCK
#endif

#ifdef MAIL_USE_MMDF
extern int lk_open (), lk_close ();
#endif

/* Cancel substitutions made by config.h for Emacs.  */
#undef open
#undef read
#undef write
#undef close

static void fatal (char *, char*);
static void error (char *, char *, char *);
static void pfatal_with_name (char *);
static void pfatal_and_delete (char *);
static char *concat (char *, char *, char *);
static long *xmalloc (unsigned int);
#ifdef MAIL_USE_POP
static int popmail (char *, char *, char *);
static int pop_retr (popserver server, int msgno, int (*action)(), void *arg);
static int mbx_write (char *, FILE *);
static int mbx_delimit_begin (FILE *);
static int mbx_delimit_end (FILE *);
static struct re_pattern_buffer* compile_regex (char* regexp_pattern);
static int pop_search_top (popserver server, int msgno, int lines, 
			   struct re_pattern_buffer* regexp);
#endif

/* Nonzero means this is name of a lock file to delete on fatal error.  */
char *delete_lockname;

int verbose=0;
#ifdef MAIL_USE_POP
int reverse=0;
int keep_messages=0;
struct re_pattern_buffer* regexp_pattern=0;
int match_lines=10;
#endif

#define VERBOSE(x) if (verbose) { printf x; fflush(stdout); }

struct option longopts[] =
{
  { "inbox",			required_argument,	   NULL,	'i'	},
  { "outfile",			required_argument,	   NULL,	'o'	},
#ifdef MAIL_USE_POP
  { "password",			required_argument,	   NULL,	'p'	},
  { "reverse-pop-order",		no_argument,		   NULL,	'x'	},
  { "keep-messages",		no_argument,		   NULL,	'k'	},
  { "regex",			required_argument,	   NULL,	'r' 	},
  { "match-lines",		required_argument,	   NULL,	'l' 	},
#endif
  { "verbose", 			no_argument,		   NULL,	'v'	},
  { 0 }
};

int
main (int argc, char *argv[])
{
  char *inname=0, *outname=0, *poppass=0;
#ifndef DISABLE_DIRECT_ACCESS
  int indesc, outdesc;
  int nread;
  int status;
#endif

#ifndef MAIL_USE_SYSTEM_LOCK
  struct stat st;
  long now;
  int tem;
  char *lockname, *p;
  char *tempname;
  int desc;
#endif /* not MAIL_USE_SYSTEM_LOCK */

  delete_lockname = 0;

  while (1)
    {
#ifdef MAIL_USE_POP
      char* optstring = "i:o:p:l:r:xvk";
#else
      char* optstring = "i:o:v";
#endif
      int opt = getopt_long (argc, argv, optstring, longopts, 0);
  
      if (opt == EOF)
	break;

      switch (opt)
	{
	case 0:
	  break;
	case 1:			/* one of the standard arguments seen */
	  if (!inname)
	    inname = optarg;
	  else if (!outname)
	    outname = optarg;
	  else
	    poppass = optarg;
	  break;

	case 'i':		/* infile */
	  inname = optarg;
	  break;
	  
	case 'o':		/* outfile */
	  outname = optarg;
	  break;
#ifdef MAIL_USE_POP
	case 'p':		/* pop password */
	  poppass = optarg;	
	  break;
	case 'k':		keep_messages=1;	break;
	case 'x':		reverse = 1;		break;
	case 'l':		/* lines to match */
	  match_lines = atoi (optarg);
	  break;

	case 'r':		/* regular expression */
	  regexp_pattern = compile_regex (optarg);
	  break;
#endif
	case 'v':		verbose = 1;	break;
	}
    }

  while (optind < argc)
      {
	  if (!inname)
	      inname = argv[optind];
	  else if (!outname)
	      outname = argv[optind];
	  else
	      poppass = argv[optind];
	  optind++;
      }
    
  if (!inname || !outname)
    {
      fprintf (stderr, "Usage: movemail [-rvxk] [-l lines ] [-i] inbox [-o] destfile [[-p] POP-password]\n");
      exit(1);
    }

#ifdef MAIL_USE_MMDF
  mmdf_init (argv[0]);
#endif

  if (*outname == 0)
    fatal ("Destination file name is empty", 0);

  /* Check access to output file.  */
  if (access (outname, F_OK) == 0 && access (outname, W_OK) != 0)
    pfatal_with_name (outname);

  /* Also check that outname's directory is writable to the real uid.  */
  {
    char *buf = (char *) xmalloc (strlen (outname) + 1);
    char *cp;
    strcpy (buf, outname);
    cp = buf + strlen (buf);
    while (cp > buf && !IS_DIRECTORY_SEP (cp[-1]))
      *--cp = 0;
    if (cp == buf)
      *cp++ = '.';
    if (access (buf, W_OK) != 0)
      pfatal_with_name (buf);
    free (buf);
  }

#ifdef MAIL_USE_POP
  if (!strncmp (inname, "po:", 3))
    {
      int retcode = popmail (inname + 3, outname, poppass);
      exit (retcode);
    }

  setuid (getuid ());
#endif /* MAIL_USE_POP */

#ifndef DISABLE_DIRECT_ACCESS

  /* Check access to input file.  */
  if (access (inname, R_OK | W_OK) != 0)
    pfatal_with_name (inname);

#ifndef MAIL_USE_MMDF
#ifndef MAIL_USE_SYSTEM_LOCK
  /* Use a lock file named after our first argument with .lock appended:
     If it exists, the mail file is locked.  */
  /* Note: this locking mechanism is *required* by the mailer
     (on systems which use it) to prevent loss of mail.

     On systems that use a lock file, extracting the mail without locking
     WILL occasionally cause loss of mail due to timing errors!

     So, if creation of the lock file fails
     due to access permission on the mail spool directory,
     you simply MUST change the permission
     and/or make movemail a setgid program
     so it can create lock files properly.

     You might also wish to verify that your system is one
     which uses lock files for this purpose.  Some systems use other methods.

     If your system uses the `flock' system call for mail locking,
     define MAIL_USE_SYSTEM_LOCK in config.h or the s-*.h file
     and recompile movemail.  If the s- file for your system
     should define MAIL_USE_SYSTEM_LOCK but does not, send a bug report
     to bug-gnu-emacs@prep.ai.mit.edu so we can fix it.  */

  lockname = concat (inname, ".lock", "");
  tempname = (char *) xmalloc (strlen (inname) + strlen ("EXXXXXX") + 1);
  strcpy (tempname, inname);
  p = tempname + strlen (tempname);
  while (p != tempname && !IS_DIRECTORY_SEP (p[-1]))
    p--;
  *p = 0;
  strcpy (p, "EXXXXXX");
  mktemp (tempname);
  unlink (tempname);

  while (1)
    {
      /* Create the lock file, but not under the lock file name.  */
      /* Give up if cannot do that.  */
      desc = open (tempname, O_WRONLY | O_CREAT | O_EXCL, 0666);
      if (desc < 0)
	{
	  char *message = (char *) xmalloc (strlen (tempname) + 50);
	  sprintf (message, "%s--see source file lib-src/movemail.c",
		   tempname);
	  pfatal_with_name (message);
	}
      close (desc);

      tem = link (tempname, lockname);
      unlink (tempname);
      if (tem >= 0)
	break;
      sleep (1);

      /* If lock file is five minutes old, unlock it.
	 Five minutes should be good enough to cope with crashes
	 and wedgitude, and long enough to avoid being fooled
	 by time differences between machines.  */
      if (stat (lockname, &st) >= 0)
	{
	  now = time (0);
	  if (st.st_ctime < now - 300)
	    unlink (lockname);
	}
    }

  delete_lockname = lockname;
#endif /* not MAIL_USE_SYSTEM_LOCK */
#endif /* not MAIL_USE_MMDF */

  if (fork () == 0)
    {
      setuid (getuid ());

#ifndef MAIL_USE_MMDF
#ifdef MAIL_USE_SYSTEM_LOCK
      indesc = open (inname, O_RDWR);
#else  /* if not MAIL_USE_SYSTEM_LOCK */
      indesc = open (inname, O_RDONLY);
#endif /* not MAIL_USE_SYSTEM_LOCK */
#else  /* MAIL_USE_MMDF */
      indesc = lk_open (inname, O_RDONLY, 0, 0, 10);
#endif /* MAIL_USE_MMDF */

      if (indesc < 0)
	pfatal_with_name (inname);

#if defined (BSD) || defined (XENIX)
      /* In case movemail is setuid to root, make sure the user can
	 read the output file.  */
      /* This is desirable for all systems
	 but I don't want to assume all have the umask system call */
      umask (umask (0) & 0333);
#endif /* BSD or Xenix */
      outdesc = open (outname, O_WRONLY | O_CREAT | O_EXCL, 0666);
      if (outdesc < 0)
	pfatal_with_name (outname);
#ifdef MAIL_USE_SYSTEM_LOCK
#ifdef MAIL_USE_LOCKF
      if (lockf (indesc, F_LOCK, 0) < 0) pfatal_with_name (inname);
#else /* not MAIL_USE_LOCKF */
#ifdef XENIX
      if (locking (indesc, LK_RLCK, 0L) < 0) pfatal_with_name (inname);
#else
#ifdef WINDOWSNT
      if (locking (indesc, LK_RLCK, -1L) < 0) pfatal_with_name (inname);
#else
      if (flock (indesc, LOCK_EX) < 0) pfatal_with_name (inname);
#endif
#endif
#endif /* not MAIL_USE_LOCKF */
#endif /* MAIL_USE_SYSTEM_LOCK */

      {
	char buf[1024];

	while (1)
	  {
	    nread = read (indesc, buf, sizeof buf);
	    if (nread != write (outdesc, buf, nread))
	      {
		int saved_errno = errno;
		unlink (outname);
		errno = saved_errno;
		pfatal_with_name (outname);
	      }
	    if (nread < sizeof buf)
	      break;
	  }
      }

#ifdef BSD
      if (fsync (outdesc) < 0)
	pfatal_and_delete (outname);
#endif

      /* Check to make sure no errors before we zap the inbox.  */
      if (close (outdesc) != 0)
	pfatal_and_delete (outname);

#ifdef MAIL_USE_SYSTEM_LOCK
#if defined (STRIDE) || defined (XENIX) || defined (WINDOWSNT)
      /* Stride, xenix have file locking, but no ftruncate.  This mess will do. */
      close (open (inname, O_CREAT | O_TRUNC | O_RDWR, 0666));
#else
      ftruncate (indesc, 0L);
#endif /* STRIDE or XENIX */
#endif /* MAIL_USE_SYSTEM_LOCK */

#ifdef MAIL_USE_MMDF
      lk_close (indesc, 0, 0, 0);
#else
      close (indesc);
#endif

#ifndef MAIL_USE_SYSTEM_LOCK
      /* Delete the input file; if we can't, at least get rid of its
	 contents.  */
#ifdef MAIL_UNLINK_SPOOL
      /* This is generally bad to do, because it destroys the permissions
	 that were set on the file.  Better to just empty the file.  */
      if (unlink (inname) < 0 && errno != ENOENT)
#endif /* MAIL_UNLINK_SPOOL */
	creat (inname, 0600);
#endif /* not MAIL_USE_SYSTEM_LOCK */

      exit (0);
    }

  wait (&status);
  if (!WIFEXITED (status))
    exit (1);
  else if (WEXITSTATUS (status) != 0)
    exit (WEXITSTATUS (status));

#if !defined (MAIL_USE_MMDF) && !defined (MAIL_USE_SYSTEM_LOCK)
  unlink (lockname);
#endif /* not MAIL_USE_MMDF and not MAIL_USE_SYSTEM_LOCK */

#endif /* ! DISABLE_DIRECT_ACCESS */

  return 0;
}

/* Print error message and exit.  */

static void
fatal (char *s1, char *s2)
{
  if (delete_lockname)
    unlink (delete_lockname);
  error (s1, s2, NULL);
  exit (1);
}

/* Print error message.  `s1' is printf control string, `s2' is arg for it. */

static void
error (char *s1, char *s2, char *s3)
{
  fprintf (stderr, "movemail: ");
  fprintf (stderr, s1, s2, s3);
  fprintf (stderr, "\n");
}

static void
pfatal_with_name (char *name)
{
  char *s = concat ("", strerror (errno), " for %s");
  fatal (s, name);
}

static void
pfatal_and_delete (char *name)
{
  char *s = concat ("", strerror (errno), " for %s");
  unlink (name);
  fatal (s, name);
}

/* Return a newly-allocated string whose contents concatenate those of s1, s2, s3.  */

static char *
concat (char *s1, char *s2, char *s3)
{
  int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
  char *result = (char *) xmalloc (len1 + len2 + len3 + 1);

  strcpy (result, s1);
  strcpy (result + len1, s2);
  strcpy (result + len1 + len2, s3);
  *(result + len1 + len2 + len3) = 0;

  return result;
}

/* Like malloc but get fatal error if memory is exhausted.  */

static long *
xmalloc (unsigned int size)
{
  long *result = (long *) malloc (size);
  if (!result)
    fatal ("virtual memory exhausted", 0);
  return result;
}

/* This is the guts of the interface to the Post Office Protocol.  */

#ifdef MAIL_USE_POP

#ifndef WINDOWSNT
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#else
#undef _WINSOCKAPI_
#include <winsock.h>
#endif
#include <stdio.h>
#include <pwd.h>

#define POP_ERROR 	(-1)
#define POP_RETRIEVED (0)
#define POP_DONE (1)

char *progname;
FILE *sfi;
FILE *sfo;
char ibuffer[BUFSIZ];
char obuffer[BUFSIZ];
char Errmsg[80];

static int
popmail (char *user, char *outfile, char *password)
{
  int nmsgs, nbytes;
  register int i, idx;
  int mbfi;
  short* retrieved_list;
  FILE *mbf;
  popserver server;

  VERBOSE(("opening server\r"));
  server = pop_open (0, user, password, POP_NO_GETPASS);
  if (! server)
    {
      error (pop_error, NULL, NULL);
      return (1);
    }

  VERBOSE(("stat'ing messages\r"));
  if (pop_stat (server, &nmsgs, &nbytes))
    {
      error (pop_error, NULL, NULL);
      return (1);
    }

  if (!nmsgs)
    {
      VERBOSE(("closing server\n"));
      pop_close (server);
      return (0);
    }

  /* build a retrieved table */
  retrieved_list = (short*) xmalloc (sizeof (short) * (nmsgs+1));
  memset (retrieved_list, 0, sizeof (short) * (nmsgs+1));

  mbfi = open (outfile, O_WRONLY | O_CREAT | O_EXCL, 0666);
  if (mbfi < 0)
    {
      pop_close (server);
      error ("Error in open: %s, %s", strerror (errno), outfile);
      return (1);
    }
#ifndef __CYGWIN32__
  fchown (mbfi, getuid (), -1);
#endif

  if ((mbf = fdopen (mbfi, "wb")) == NULL)
    {
      pop_close (server);
      error ("Error in fdopen: %s", strerror (errno), NULL);
      close (mbfi);
      unlink (outfile);
      return (1);
    }

  for (idx = 0; idx < nmsgs; idx++)
    {
      i = reverse ? nmsgs - idx : idx + 1;
      VERBOSE(("checking message %d     \r", i));
      
      if (!regexp_pattern 
	  || 
	  pop_search_top (server, i, match_lines, regexp_pattern) == POP_RETRIEVED)
	{
	  VERBOSE(("retrieving message %d     \r", i));
          mbx_delimit_begin (mbf);
	  if (pop_retr (server, i, mbx_write, mbf) != POP_RETRIEVED)
	    {
	      error (Errmsg, NULL, NULL);
	      close (mbfi);
	      return (1);
	    }

	  retrieved_list[i]=1;

	  mbx_delimit_end (mbf);
	  fflush (mbf);
	  if (ferror (mbf))
	    {
	      error ("Error in fflush: %s", strerror (errno), NULL);
	      pop_close (server);
	      close (mbfi);
	      return (1);
	    }
	}
    }

  /* On AFS, a call to write only modifies the file in the local
   *     workstation's AFS cache.  The changes are not written to the server
   *      until a call to fsync or close is made.  Users with AFS home
   *      directories have lost mail when over quota because these checks were
   *      not made in previous versions of movemail. */

#ifdef BSD
  if (fsync (mbfi) < 0)
    {
      error ("Error in fsync: %s", strerror (errno), NULL);
      return (1);
    }
#endif

  if (close (mbfi) == -1)
    {
      error ("Error in close: %s", strerror (errno), NULL);
      return (1);
    }

  if (!keep_messages)
    {
      for (i = 1; i <= nmsgs; i++)
	{
	  if (retrieved_list[i] == 1)
	    {
	      VERBOSE(("deleting message %d     \r", i));
	      if (pop_delete (server, i))
		{
		  error (pop_error, NULL, NULL);
		  pop_close (server);
		  return (1);
		}
	    }
	}
    }

  VERBOSE(("closing server             \n"));
  if (pop_quit (server))
    {
      error (pop_error, NULL, NULL);
      return (1);
    }
    
  return (0);
}

static int
pop_retr (popserver server, int msgno, int (*action)(), void *arg)
{
  char *line;
  int ret;

  if (pop_retrieve_first (server, msgno, &line))
    {
      strncpy (Errmsg, pop_error, sizeof (Errmsg));
      Errmsg[sizeof (Errmsg)-1] = '\0';
      return (POP_ERROR);
    }

  while (! (ret = pop_retrieve_next (server, &line)))
    {
      if (! line)
	break;

      if ((*action)(line, arg) != POP_RETRIEVED)
	{
	  strcpy (Errmsg, strerror (errno));
	  pop_close (server);
	  return (POP_ERROR);
	}
    }

  if (ret)
    {
      strncpy (Errmsg, pop_error, sizeof (Errmsg));
      Errmsg[sizeof (Errmsg)-1] = '\0';
      return (POP_ERROR);
    }

  return (POP_RETRIEVED);
}

/* search the top lines of each message looking for a match */
static int
pop_search_top (popserver server, int msgno, int lines, struct re_pattern_buffer* regexp)
{
  char *line;
  int ret;
  int match = POP_DONE;

  if (pop_top_first (server, msgno, lines, &line))
    {
      strncpy (Errmsg, pop_error, sizeof (Errmsg));
      Errmsg[sizeof (Errmsg)-1] = '\0';
      return (POP_ERROR);
    }

  while (! (ret = pop_top_next (server, &line)))
    {
      if (! line)
	break;

      /*      VERBOSE (("checking %s\n", line));*/
      if (match != POP_RETRIEVED)
	{
	  if ((ret = re_match (regexp, line, strlen (line), 0, 0)) == -2 )
	    {
	      strcpy (Errmsg, "error in regular expression");
	      pop_close (server);
	      return (POP_ERROR);
	    }
	  else if (ret >=0)
	    {
	      match = POP_RETRIEVED;
	    }
	}
    }

  if (ret)
    {
      strncpy (Errmsg, pop_error, sizeof (Errmsg));
      Errmsg[sizeof (Errmsg)-1] = '\0';
      return (POP_ERROR);
    }

  return match;
}

/* Do this as a macro instead of using strcmp to save on execution time. */
#define IS_FROM_LINE(a) ((a[0] == 'F') \
			 && (a[1] == 'r') \
			 && (a[2] == 'o') \
			 && (a[3] == 'm') \
			 && (a[4] == ' '))

static int
mbx_write (char *line, FILE *mbf)
{
  if (IS_FROM_LINE (line))
    {
      if (fputc ('>', mbf) == EOF)
	return (POP_ERROR);
    }
  if (fputs (line, mbf) == EOF) 
    return (POP_ERROR);
  if (fputc (0x0a, mbf) == EOF)
    return (POP_ERROR);
  return (POP_RETRIEVED);
}

static int
mbx_delimit_begin (FILE *mbf)
{
  if (fputs ("\f\n0, unseen,,\n", mbf) == EOF)
    return (POP_ERROR);
  return (POP_RETRIEVED);
}

static int
mbx_delimit_end (FILE *mbf)
{
  if (putc ('\037', mbf) == EOF)
    return (POP_ERROR);
  return (POP_RETRIEVED);
}

/* Turn a name, which is an ed-style (but Emacs syntax) regular
   expression, into a real regular expression by compiling it. */
static struct re_pattern_buffer*
compile_regex (char* pattern)
{
  char *err;
  struct re_pattern_buffer *patbuf=0;
  
  patbuf = (struct re_pattern_buffer*) xmalloc (sizeof (struct re_pattern_buffer));
  patbuf->translate = NULL;
  patbuf->fastmap = NULL;
  patbuf->buffer = NULL;
  patbuf->allocated = 0;

  err = (char*) re_compile_pattern (pattern, strlen (pattern), patbuf);
  if (err != NULL)
    {
      error ("%s while compiling pattern", err, NULL);
      return 0;
    }

  return patbuf;
}



#endif /* MAIL_USE_POP */

#ifndef HAVE_STRERROR
char *
strerror (int errnum)
{
  extern char *sys_errlist[];
  extern int sys_nerr;

  if (errnum >= 0 && errnum < sys_nerr)
    return sys_errlist[errnum];
  return (char *) "Unknown error";
}

#endif /* ! HAVE_STRERROR */