/* filesubr.c --- subroutines for dealing with files
   Gratuitously adapted toward VMS quirks.

   Jim Blandy <jimb@cyclic.com>
   Benjamin J. Lee <benjamin@cyclic.com>

   This file is part of GNU CVS.

   GNU CVS 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.

   This program 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.  */

#include "cvs.h"
#include <assert.h>

static int deep_remove_dir PROTO((const char *path));

/*
 * Copies "from" to "to".
 */
void
copy_file (from_file, to_file)
    const char *from_file;
    const char *to_file;
{
    char from[PATH_MAX], to[PATH_MAX];
    struct stat sb;
    struct utimbuf t;
    int fdin, fdout;

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(from_file))
      strcpy(from, from_file);
    else
      sprintf(from, "./%s", from_file);

    if (isabsolute(to_file))
      strcpy(to, to_file);
    else
      sprintf(to, "./%s", to_file);

    if (trace)
#ifdef SERVER_SUPPORT
	(void) fprintf (stderr, "%c-> copy(%s,%s)\n",
			(server_active) ? 'S' : ' ', from, to);
#else
	(void) fprintf (stderr, "-> copy(%s,%s)\n", from, to);
#endif
    if (noexec)
	return;

    if ((fdin = open (from, O_RDONLY)) < 0)
	error (1, errno, "cannot open %s for copying", from);
    if (fstat (fdin, &sb) < 0)
	error (1, errno, "cannot fstat %s", from);
    if ((fdout = creat (to, (int) sb.st_mode & 07777)) < 0)
	error (1, errno, "cannot create %s for copying", to);
    if (sb.st_size > 0)
    {
	char buf[BUFSIZ];
	int n;

	for (;;) 
	{
	    n = read (fdin, buf, sizeof(buf));
	    if (n == -1)
	    {
#ifdef EINTR
		if (errno == EINTR)
		    continue;
#endif
		error (1, errno, "cannot read file %s for copying", from);
	    }
            else if (n == 0) 
		break;
  
	    if (write(fdout, buf, n) != n) {
		error (1, errno, "cannot write file %s for copying", to);
	    }
	}

#ifdef HAVE_FSYNC
	if (fsync (fdout)) 
	    error (1, errno, "cannot fsync file %s after copying", to);
#endif
    }

    if (close (fdin) < 0) 
	error (0, errno, "cannot close %s", from);
    if (close (fdout) < 0)
	error (1, errno, "cannot close %s", to);

    /* now, set the times for the copied file to match those of the original */
    memset ((char *) &t, 0, sizeof (t));
    t.actime = sb.st_atime;
    t.modtime = sb.st_mtime;
    (void) utime (to, &t);
}

/* FIXME-krp: these functions would benefit from caching the char * &
   stat buf.  */

/*
 * Returns non-zero if the argument file is a directory, or is a symbolic
 * link which points to a directory.
 */
int
isdir (file)
    const char *file;
{
    struct stat sb;

    if (stat (file, &sb) < 0)
	return (0);
    return (S_ISDIR (sb.st_mode));
}

/*
 * Returns non-zero if the argument file is a symbolic link.
 */
int
islink (file)
    const char *file;
{
#ifdef S_ISLNK
    struct stat sb;

    if (lstat (file, &sb) < 0)
	return (0);
    return (S_ISLNK (sb.st_mode));
#else
    return (0);
#endif
}

/*
 * Returns non-zero if the argument file exists.
 */
int
isfile (file)
    const char *file;
{
    return isaccessible(file, F_OK);
}

/*
 * Returns non-zero if the argument file is readable.
 */
int
isreadable (file)
    const char *file;
{
    return isaccessible(file, R_OK);
}

/*
 * Returns non-zero if the argument file is writable.
 */
int
iswritable (file)
    const char *file;
{
    return isaccessible(file, W_OK);
}

/*
 * Returns non-zero if the argument file is accessable according to
 * mode.  If compiled with SETXID_SUPPORT also works if cvs has setxid
 * bits set.
 */
int
isaccessible (file, mode)
    const char *file;
    const int mode;
{
#ifdef SETXID_SUPPORT
    struct stat sb;
    int umask = 0;
    int gmask = 0;
    int omask = 0;
    int uid;
    
    if (stat(file, &sb) == -1)
	return 0;
    if (mode == F_OK)
	return 1;

    uid = geteuid();
    if (uid == 0)		/* superuser */
    {
	if (mode & X_OK)
	    return sb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH);
	else
	    return 1;
    }
	
    if (mode & R_OK)
    {
	umask |= S_IRUSR;
	gmask |= S_IRGRP;
	omask |= S_IROTH;
    }
    if (mode & W_OK)
    {
	umask |= S_IWUSR;
	gmask |= S_IWGRP;
	omask |= S_IWOTH;
    }
    if (mode & X_OK)
    {
	umask |= S_IXUSR;
	gmask |= S_IXGRP;
	omask |= S_IXOTH;
    }

    if (sb.st_uid == uid)
	return (sb.st_mode & umask) == umask;
    else if (sb.st_gid == getegid())
	return (sb.st_mode & gmask) == gmask;
    else
	return (sb.st_mode & omask) == omask;
#else
    return access(file, mode) == 0;
#endif
}

/*
 * Open a file and die if it fails
 */
FILE *
open_file (name, mode)
    const char *name;
    const char *mode;
{
    FILE *fp;

    if ((fp = fopen (name, mode)) == NULL)
	error (1, errno, "cannot open %s", name);
    return (fp);
}

/*
 * Make a directory and die if it fails
 */
void
make_directory (name)
    const char *name;
{
    struct stat sb;

    if (stat (name, &sb) == 0 && (!S_ISDIR (sb.st_mode)))
	    error (0, 0, "%s already exists but is not a directory", name);
    if (!noexec && mkdir (name, 0777) < 0)
	error (1, errno, "cannot make directory %s", name);
}

/*
 * Make a path to the argument directory, printing a message if something
 * goes wrong.
 */
void
make_directories (name)
    const char *name;
{
    char *cp;

    if (noexec)
	return;

    if (mkdir (name, 0777) == 0 || errno == EEXIST)
	return;
    if (! existence_error (errno))
    {
	error (0, errno, "cannot make path to %s", name);
	return;
    }
    if ((cp = strrchr (name, '/')) == NULL)
	return;
    *cp = '\0';
    make_directories (name);
    *cp++ = '/';
    if (*cp == '\0')
	return;
    (void) mkdir (name, 0777);
}

/* Create directory NAME if it does not already exist; fatal error for
   other errors.  Returns 0 if directory was created; 1 if it already
   existed.  */
int
mkdir_if_needed (name)
    char *name;
{
    if (mkdir (name, 0777) < 0)
    {
	if (errno != EEXIST
#ifdef EACCESS
	    /* This was copied over from the OS/2 code; I would guess it
	       isn't needed here but that has not been verified.  */
	    && errno != EACCESS
#endif
	    )
	    error (1, errno, "cannot make directory %s", name);
	return 1;
    }
    return 0;
}

/*
 * Change the mode of a file, either adding write permissions, or removing
 * all write permissions.  Either change honors the current umask setting.
 */
void
xchmod (fname_file, writable)
    char *fname_file;
    int writable;
{
    char fname[PATH_MAX];
    struct stat sb;
    mode_t mode, oumask;

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(fname_file))
      strcpy(fname, fname_file);
    else
      sprintf(fname, "./%s", fname_file);

    if (stat (fname, &sb) < 0)
    {
	if (!noexec)
	    error (0, errno, "cannot stat %s", fname);
	return;
    }
    oumask = umask (0);
    (void) umask (oumask);
    if (writable)
    {
	mode = sb.st_mode | (~oumask
			     & (((sb.st_mode & S_IRUSR) ? S_IWUSR : 0)
				| ((sb.st_mode & S_IRGRP) ? S_IWGRP : 0)
				| ((sb.st_mode & S_IROTH) ? S_IWOTH : 0)));
    }
    else
    {
	mode = sb.st_mode & ~(S_IWRITE | S_IWGRP | S_IWOTH) & ~oumask;
    }

    if (trace)
#ifdef SERVER_SUPPORT
	(void) fprintf (stderr, "%c-> chmod(%s,%o)\n",
			(server_active) ? 'S' : ' ', fname, mode);
#else
	(void) fprintf (stderr, "-> chmod(%s,%o)\n", fname, mode);
#endif
    if (noexec)
	return;

    if (chmod (fname, mode) < 0)
	error (0, errno, "cannot change mode of file %s", fname);
}

/*
 * Rename a file and die if it fails
 */
void
rename_file (from_file, to_file)
    const char *from_file;
    const char *to_file;
{
    char from[PATH_MAX], to[PATH_MAX];

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(from_file))
      strcpy(from, from_file);
    else
      sprintf(from, "./%s", from_file);

    if (isabsolute(to_file))
      strcpy(to, to_file);
    else
      sprintf(to, "./%s", to_file);

    if (trace)
#ifdef SERVER_SUPPORT
	(void) fprintf (stderr, "%c-> rename(%s,%s)\n",
			(server_active) ? 'S' : ' ', from, to);
#else
	(void) fprintf (stderr, "-> rename(%s,%s)\n", from, to);
#endif
    if (noexec)
	return;

    if (rename (from, to) < 0)
	error (1, errno, "cannot rename file %s to %s", from, to);
}

/*
 * unlink a file, if possible.
 */
int
unlink_file (f_file)
    const char *f_file;
{
    char f[PATH_MAX];

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(f_file))
      strcpy(f, f_file);
    else
      sprintf(f, "./%s", f_file);

    if (trace)
#ifdef SERVER_SUPPORT
	(void) fprintf (stderr, "%c-> unlink(%s)\n",
			(server_active) ? 'S' : ' ', f);
#else
	(void) fprintf (stderr, "-> unlink(%s)\n", f);
#endif
    if (noexec)
	return (0);

    return (vms_unlink (f));
}

/*
 * Unlink a file or dir, if possible.  If it is a directory do a deep
 * removal of all of the files in the directory.  Return -1 on error
 * (in which case errno is set).
 */
int
unlink_file_dir (f_file)
    const char *f_file;
{
    char f[PATH_MAX];

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(f_file))
      strcpy(f, f_file);
    else
      sprintf(f, "./%s", f_file);

    if (trace)
#ifdef SERVER_SUPPORT
	(void) fprintf (stderr, "%c-> unlink_file_dir(%s)\n",
			(server_active) ? 'S' : ' ', f);
#else
	(void) fprintf (stderr, "-> unlink_file_dir(%s)\n", f);
#endif
    if (noexec)
	return (0);

    if (vms_unlink (f) != 0)
    {
	/* under NEXTSTEP errno is set to return EPERM if
	 * the file is a directory,or if the user is not
	 * allowed to read or write to the file.
	 * [This is probably a bug in the O/S]
	 * other systems will return EISDIR to indicate
	 * that the path is a directory.
	 */
        if (errno == EISDIR || errno == EPERM)
                return deep_remove_dir (f);
        else
		/* The file wasn't a directory and some other
		 * error occured
		 */
                return -1;
    }
    /* We were able to remove the file from the disk */
    return 0;
}

/* Remove a directory and everything it contains.  Returns 0 for
 * success, -1 for failure (in which case errno is set).
 */

static int
deep_remove_dir (path)
    const char *path;
{
    DIR		  *dirp;
    struct dirent *dp;
    char	   buf[PATH_MAX];

    if (rmdir (path) != 0 && (errno == ENOTEMPTY || errno == EEXIST)) 
    {
	if ((dirp = CVS_OPENDIR (path)) == NULL)
	    /* If unable to open the directory return
	     * an error
	     */
	    return -1;

	while ((dp = CVS_READDIR (dirp)) != NULL)
	{
	    if (strcmp (dp->d_name, ".") == 0 ||
			strcmp (dp->d_name, "..") == 0)
		continue;

	    sprintf (buf, "%s/%s", path, dp->d_name);

	    if (vms_unlink (buf) != 0 )
	    {
		if (errno == EISDIR || errno == EPERM)
		{
		    if (deep_remove_dir (buf))
		    {
			CVS_CLOSEDIR (dirp);
			return -1;
		    }
		}
		else
		{
		    /* buf isn't a directory, or there are
		     * some sort of permision problems
		     */
		    CVS_CLOSEDIR (dirp);
		    return -1;
		}
	    }
	}
	CVS_CLOSEDIR (dirp);
	return rmdir (path);
	}

    /* Was able to remove the directory return 0 */
    return 0;
}

/* Read NCHARS bytes from descriptor FD into BUF.
   Return the number of characters successfully read.
   The number returned is always NCHARS unless end-of-file or error.  */
static size_t
block_read (fd, buf, nchars)
    int fd;
    char *buf;
    size_t nchars;
{
    char *bp = buf;
    size_t nread;

    do 
    {
	nread = read (fd, bp, nchars);
	if (nread == (size_t)-1)
	{
#ifdef EINTR
	    if (errno == EINTR)
		continue;
#endif
	    return (size_t)-1;
	}

	if (nread == 0)
	    break; 

	bp += nread;
	nchars -= nread;
    } while (nchars != 0);

    return bp - buf;
} 

    
/*
 * Compare "file1" to "file2". Return non-zero if they don't compare exactly.
 */
int
xcmp (file1_file, file2_file)
    const char *file1_file;
    const char *file2_file;
{
    char file1[PATH_MAX], file2[PATH_MAX];
    char *buf1, *buf2;
    struct stat sb1, sb2;
    int fd1, fd2;
    int ret;

    /* Prefer local relative paths to files at expense of logical name
       access to files. */

    if (isabsolute(file1_file))
      strcpy(file1, file1_file);
    else
      sprintf(file1, "./%s", file1_file);

    if (isabsolute(file2_file))
      strcpy(file2, file2_file);
    else
      sprintf(file2, "./%s", file2_file);

    if ((fd1 = open (file1, O_RDONLY)) < 0)
	error (1, errno, "cannot open file %s for comparing", file1);
    if ((fd2 = open (file2, O_RDONLY)) < 0)
	error (1, errno, "cannot open file %s for comparing", file2);
    if (fstat (fd1, &sb1) < 0)
	error (1, errno, "cannot fstat %s", file1);
    if (fstat (fd2, &sb2) < 0)
	error (1, errno, "cannot fstat %s", file2);

    /* A generic file compare routine might compare st_dev & st_ino here 
       to see if the two files being compared are actually the same file.
       But that won't happen in CVS, so we won't bother. */

    if (sb1.st_size != sb2.st_size)
	ret = 1;
    else if (sb1.st_size == 0)
	ret = 0;
    else
    {
	/* FIXME: compute the optimal buffer size by computing the least
	   common multiple of the files st_blocks field */
	size_t buf_size = 8 * 1024;
	size_t read1;
	size_t read2;

	buf1 = xmalloc (buf_size);
	buf2 = xmalloc (buf_size);

	do 
	{
	    read1 = block_read (fd1, buf1, buf_size);
	    if (read1 == (size_t)-1)
		error (1, errno, "cannot read file %s for comparing", file1);

	    read2 = block_read (fd2, buf2, buf_size);
	    if (read2 == (size_t)-1)
		error (1, errno, "cannot read file %s for comparing", file2);

	    assert (read1 == read2);

	    ret = memcmp(buf1, buf2, read1);
	} while (ret == 0 && read1 == buf_size);

	free (buf1);
	free (buf2);
    }
	
    (void) close (fd1);
    (void) close (fd2);
    return (ret);
}

unsigned char
VMS_filename_classes[] =
{
    0x00,0x01,0x02,0x03, 0x04,0x05,0x06,0x07,
    0x08,0x09,0x0a,0x0b, 0x0c,0x0d,0x0e,0x0f,
    0x10,0x11,0x12,0x13, 0x14,0x15,0x16,0x17,
    0x18,0x19,0x1a,0x1b, 0x1c,0x1d,0x1e,0x1f,
    0x20,0x21,0x22,0x23, 0x24,0x25,0x26,0x27,
    0x28,0x29,0x2a,0x2b, 0x2c,0x2d,0x2e,0x2f,
    0x30,0x31,0x32,0x33, 0x34,0x35,0x36,0x37,
    0x38,0x39,0x3a,0x3b, 0x3c,0x3d,0x3e,0x3f,
    0x40,0x61,0x62,0x63, 0x64,0x65,0x66,0x67,
    0x68,0x69,0x6a,0x6b, 0x6c,0x6d,0x6e,0x6f,
    0x70,0x71,0x72,0x73, 0x74,0x75,0x76,0x77,
    0x78,0x79,0x7a,0x5b, 0x5c,0x5d,0x5e,0x5f,
    0x60,0x61,0x62,0x63, 0x64,0x65,0x66,0x67,
    0x68,0x69,0x6a,0x6b, 0x6c,0x6d,0x6e,0x6f,
    0x70,0x71,0x72,0x73, 0x74,0x75,0x76,0x77,
    0x78,0x79,0x7a,0x7b, 0x7c,0x7d,0x7e,0x7f,
    0x80,0x81,0x82,0x83, 0x84,0x85,0x86,0x87,
    0x88,0x89,0x8a,0x8b, 0x8c,0x8d,0x8e,0x8f,
    0x90,0x91,0x92,0x93, 0x94,0x95,0x96,0x97,
    0x98,0x99,0x9a,0x9b, 0x9c,0x9d,0x9e,0x9f,
    0xa0,0xa1,0xa2,0xa3, 0xa4,0xa5,0xa6,0xa7,
    0xa8,0xa9,0xaa,0xab, 0xac,0xad,0xae,0xaf,
    0xb0,0xb1,0xb2,0xb3, 0xb4,0xb5,0xb6,0xb7,
    0xb8,0xb9,0xba,0xbb, 0xbc,0xbd,0xbe,0xbf,
    0xc0,0xc1,0xc2,0xc3, 0xc4,0xc5,0xc6,0xc7,
    0xc8,0xc9,0xca,0xcb, 0xcc,0xcd,0xce,0xcf,
    0xd0,0xd1,0xd2,0xd3, 0xd4,0xd5,0xd6,0xd7,
    0xd8,0xd9,0xda,0xdb, 0xdc,0xdd,0xde,0xdf,
    0xe0,0xe1,0xe2,0xe3, 0xe4,0xe5,0xe6,0xe7,
    0xe8,0xe9,0xea,0xeb, 0xec,0xed,0xee,0xef,
    0xf0,0xf1,0xf2,0xf3, 0xf4,0xf5,0xf6,0xf7,
    0xf8,0xf9,0xfa,0xfb, 0xfc,0xfd,0xfe,0xff,
};



/* Like strcmp, but with the appropriate tweaks for file names.
   Under VMS, filenames are case-insensitive but case-preserving.
   FIXME: this should compare y.tab.c equal with y_tab.c, at least
   if fnfold is modified (see below).  */
int
fncmp (const char *n1, const char *n2)
{
    while (*n1 && *n2
           && (VMS_filename_classes[(unsigned char) *n1]
               == VMS_filename_classes[(unsigned char) *n2]))
        n1++, n2++;
    return (VMS_filename_classes[(unsigned char) *n1]
            - VMS_filename_classes[(unsigned char) *n2]);
}

/* Fold characters in FILENAME to their canonical forms.  FIXME: this
   probably should be mapping y.tab.c to y_tab.c but first we have to
   figure out whether fnfold is the right hook for that functionality
   (probable answer: yes, but it should not fold case on OS/2, VMS, or
   NT.  You see, fnfold isn't called anywhere, so we can define it to
   mean whatever makes sense.  Of course to solve the VMS y.tab.c
   problem we'd need to call it where appropriate.  It would need to
   be redocumented as "fold to a form we can create in the filesystem"
   rather than "canonical form").  The idea is that files we create
   would get thusly munged, but CVS can cope with their names being
   different the same way that the NT port copes with it if the user
   renames a file from "foo" to "FOO".

   Alternately, this kind of handling could/should go into CVS_FOPEN
   and friends (if we want to do it like the Mac port, anyway).  */
void
fnfold (char *filename)
{
    while (*filename)
    {
        *filename = FOLD_FN_CHAR (*filename);
	filename++;
    }
}

/* Generate a unique temporary filename.  Returns a pointer to a newly
 * malloc'd string containing the name.  Returns successfully or not at
 * all.
 *
 *     THIS FUNCTION IS DEPRECATED!!!  USE cvs_temp_file INSTEAD!!!
 *
 * and yes, I know about the way the rcs commands use temp files.  I think
 * they should be converted too but I don't have time to look into it right
 * now.
 */
char *
cvs_temp_name ()
{
    char *fn;
    FILE *fp;

    fp = cvs_temp_file (&fn);
    if (fp == NULL)
	error (1, errno, "Failed to create temporary file");
    if (fclose (fp) == EOF)
	error (0, errno, "Failed to close temporary file %s", fn);
    return fn;
}

/* Generate a unique temporary filename and return an open file stream
 * to the truncated file by that name
 *
 *  INPUTS
 *	filename	where to place the pointer to the newly allocated file
 *   			name string
 *
 *  OUTPUTS
 *	filename	dereferenced, will point to the newly allocated file
 *			name string.  This value is undefined if the function
 *			returns an error.
 *
 *  RETURNS
 *	An open file pointer to a read/write mode empty temporary file with the
 *	unique file name or NULL on failure.
 *
 *  ERRORS
 *	on error, errno will be set to some value either by CVS_FOPEN or
 *	whatever system function is called to generate the temporary file name
 */
/* There are at least four functions for generating temporary
 * filenames.  We use mkstemp (BSD 4.3) if possible, else tempnam (SVID 3),
 * else mktemp (BSD 4.3), and as last resort tmpnam (POSIX).  Reason is that
 * mkstemp, tempnam, and mktemp both allow to specify the directory in which
 * the temporary file will be created.
 *
 * And the _correct_ way to use the deprecated functions probably involves
 * opening file descriptors using O_EXCL & O_CREAT and even doing the annoying
 * NFS locking thing, but until I hear of more problems, I'm not going to
 * bother.
 */
FILE *cvs_temp_file (filename)
    char **filename;
{
    char *fn;
    FILE *fp;

    /* FIXME - I'd like to be returning NULL here in noexec mode, but I think
     * some of the rcs & diff functions which rely on a temp file run in
     * noexec mode too.
     */

    assert (filename != NULL);

#ifdef HAVE_MKSTEMP

    {
    int fd;

    fn = xmalloc (strlen (Tmpdir) + 11);
    sprintf (fn, "%s/%s", Tmpdir, "cvsXXXXXX" );
    fd = mkstemp (fn);

    /* a NULL return will be interpreted by callers as an error and
     * errno should still be set
     */
    if (fd == -1) fp = NULL;
    else if ((fp = CVS_FDOPEN (fd, "w+")) == NULL)
    {
	/* attempt to close and unlink the file since mkstemp returned sucessfully and
	 * we believe it's been created and opened
	 */
 	int save_errno = errno;
	if (close (fd))
	    error (0, errno, "Failed to close temporary file %s", fn);
	if (CVS_UNLINK (fn))
	    error (0, errno, "Failed to unlink temporary file %s", fn);
	errno = save_errno;
    }

    if (fp == NULL) free (fn);
    /* mkstemp is defined to open mode 0600 using glibc 2.0.7+ */
    /* FIXME - configure can probably tell us which version of glibc we are
     * linking to and not chmod for 2.0.7+
     */
    else chmod (fn, 0600);

    }

#elif HAVE_TEMPNAM

    /* tempnam has been deprecated due to under-specification */

    fn = tempnam (Tmpdir, "cvs");
    if (fn == NULL) fp = NULL;
    else if ((fp = CVS_FOPEN (fn, "w+")) == NULL) free (fn);
    else chmod (fn, 0600);

    /* tempnam returns a pointer to a newly malloc'd string, so there's
     * no need for a xstrdup
     */

#elif HAVE_MKTEMP

    /* mktemp has been deprecated due to the BSD 4.3 specification specifying
     * that XXXXXX will be replaced by a PID and a letter, creating only 26
     * possibilities, a security risk, and a race condition.
     */

    {
    char *ifn;

    ifn = xmalloc (strlen (Tmpdir) + 11);
    sprintf (ifn, "%s/%s", Tmpdir, "cvsXXXXXX" );
    fn = mktemp (ifn);

    if (fn == NULL) fp = NULL;
    else fp = CVS_FOPEN (fn, "w+");

    if (fp == NULL) free (ifn);
    else chmod (fn, 0600);

    }

#else	/* use tmpnam if all else fails */

    /* tmpnam is deprecated */

    {
    char ifn[L_tmpnam + 1];

    fn = tmpnam (ifn);

    if (fn == NULL) fp = NULL;
    else if ((fp = CVS_FOPEN (ifn, "w+")) != NULL)
    {
	fn = xstrdup (ifn);
	chmod (fn, 0600);
    }

    }

#endif

    *filename = fn;
    return fp;
}



/* char *
 * xresolvepath ( const char *path )
 *
 * Like xreadlink(), but resolve all links in a path.
 *
 * INPUTS
 *  path	The original path.
 *
 * RETURNS
 *  The path with any symbolic links expanded.
 *
 * ERRORS
 *  This function exits with a fatal error if it fails to read the link for
 *  any reason.
 */
char *
xresolvepath ( path )
    const char *path;
{
    char *hardpath;
    char *owd;

    assert ( isdir ( path ) );

    /* FIXME - If HAVE_READLINK is defined, we should probably walk the path
     * bit by bit calling xreadlink().
     */

    owd = xgetwd();
    if ( CVS_CHDIR ( path ) < 0)
	error ( 1, errno, "cannot chdir to %s", path );
    if ( ( hardpath = xgetwd() ) == NULL )
	error (1, errno, "cannot readlink %s", hardpath);
    if ( CVS_CHDIR ( owd ) < 0)
	error ( 1, errno, "cannot chdir to %s", owd );
    free (owd);
    return hardpath;
}

/* Return a pointer into PATH's last component.  */
const char *
last_component (path)
    char *path;
{
    char *last = strrchr (path, '/');

    if (last && (last != path))
        return last + 1;
    else
        return path;
}

/* Return the home directory.  Returns a pointer to storage
   managed by this function or its callees (currently getenv).  */
char *
get_homedir ()
{
    return getenv ("HOME");
}

/* Compose a path to a file in the home directory.  This is different than
 * the UNIX version since, on VMS, foo:[bar]/.cvspass is not
 * a legal filename but foo:[bar].cvspass is.
 *
 * A more clean solution would be something more along the lines of a
 * "join a directory to a filename" kind of thing which was not specific to
 * the homedir.  This should aid portability between UNIX, Mac, Windows, VMS,
 * and possibly others.  This is already handled by Perl - it might be
 * interesting to see how much of the code was written in C since Perl is under
 * the GPL and the Artistic license - we might be able to use it.
 */
char *
strcat_filename_onto_homedir (dir, file)
    const char *dir;
    const char *file;
{
    char *path = xmalloc (strlen (dir) + strlen(file) + 1);
    sprintf (path, "%s%s", dir, file);
    return path;
}

#ifndef __VMS_VER
#define __VMS_VER 0
#endif
#ifndef __DECC_VER
#define __DECC_VER 0
#endif

#if __VMS_VER < 70200000 || __DECC_VER < 50700000
/* See cvs.h for description.  On VMS this currently does nothing, although
   I think we should be expanding wildcards here.  */
void
expand_wild (argc, argv, pargc, pargv)
    int argc;
    char **argv;
    int *pargc;
    char ***pargv;
{
    int i;
    *pargc = argc;
    *pargv = (char **) xmalloc (argc * sizeof (char *));
    for (i = 0; i < argc; ++i)
        (*pargv)[i] = xstrdup (argv[i]);
}

#else  /*  __VMS_VER >= 70200000 && __DECC_VER >= 50700000  */

/* These global variables are necessary to pass information from the
 * routine that calls decc$from_vms into the callback routine.  In a
 * multi-threaded environment, access to these variables MUST be
 * serialized.
 */
static char CurWorkingDir[PATH_MAX+1];
static char **ArgvList;
static int  CurArg;
static int  MaxArgs;

static int ew_no_op (char *fname) {
    (void) fname;   /* Shut the compiler up */
    return 1;       /* Continue */
}

static int ew_add_file (char *fname) {
    char *lastslash, *firstper;
    int i;

    if (strncmp(fname,CurWorkingDir,strlen(CurWorkingDir)) == 0) {
        fname += strlen(CurWorkingDir);
    }
    lastslash = strrchr(fname,'/');
    if (!lastslash) {
        lastslash = fname;
    }
    if ((firstper=strchr(lastslash,'.')) != strrchr(lastslash,'.')) {
        /* We have two periods -- one is to separate the version off */
        *strrchr(fname,'.') = '\0';
    }
    if (firstper && firstper[1]=='\0') {
        *firstper = '\0';
    }
    /* The following code is to insure that no duplicates appear,
     * because most of the time it will just be a different version
     */
    for (i=0;  i<CurArg && strcmp(ArgvList[i],fname)!=0;  ++i) {
        ;
    }
    if (i==CurArg && CurArg<MaxArgs) {
        ArgvList[CurArg++] = xstrdup(fname);
    }
    return ArgvList[CurArg-1] != 0; /* Stop if we couldn't dup the string */
}

/* The following two routines are meant to allow future versions of new_arglist
 * routine to be multi-thread-safe.  It will be necessary in that environment
 * to serialize access to CurWorkingDir, ArgvList, MaxArg, and CurArg.  We
 * currently don't do any multi-threaded programming, so right now these
 * routines are no-ops.
 */
static void wait_and_protect_globs (void) {
    return;
}

static void release_globs (void) {
    return;
}

/*pf---------------------------------------------------------------- expand_wild
 *
 *  New Argument List - (SDS)
 *
 *  DESCRIPTION:
 *      This routine takes the argc, argv passed in from main() and returns a
 *  new argc, argv list, which simulates (to an extent) Unix-Style filename
 *  globbing with VMS wildcards.  The key difference is that it will return
 *  Unix-style filenames, i.e., no VMS file version numbers.  The complexity
 *  comes from the desire to not simply allocate 10000 argv entries.
 *
 *  INPUTS:
 *      argc - The integer argc passed into main
 *      argv - The pointer to the array of char*'s passed into main
 *
 *  OUTPUTS:
 *      pargv - A pointer to a (char **) to hold the new argv list
 *      pargc - A pointer to an int to hold the new argc
 *
 *  RETURNS:
 *      NONE
 *
 *  SIDE EFFECTS:
 *      This routine will normally modify the global statics CurArg, MaxArg,
 *  ArgvList, and CurWorkingDir.
 *
 *  NOTES:
 *      It is ok for &argc == pargc and &argv == pargv.
 *
 *------------------------------------------------------------------------------
 */
void expand_wild (int argc, char **argv, int *pargc, char ***pargv) {
    int totfiles, filesgotten;
    int i;
    int largc;
    char **largv;

    /* This first loop is to find out AT MOST how big to make the
     * pargv array.
     */
    for (totfiles=0,i=0;  i<argc;  ++i) {
        char *arg = argv[i];

        if (arg != 0 && (   strchr(arg,' ') != 0
                         || strcmp(arg,".") == 0
                         || strcmp(arg,"..") == 0) ) {
            ++totfiles;
        }else if (arg != 0) {
            int num;
            char *p = arg;
            /* Handle comma-separated filelists */
            while ( (p=strchr(p,',')) != 0) {
                *p = '\0';
                num = decc$from_vms (arg, ew_no_op, 1);
                totfiles += num>0 ? num : 1;
                *p++ = ',';
                arg = p;
            }
            if (*arg != '\0') {
                num = decc$from_vms (arg, ew_no_op, 1);
                totfiles += num>0 ? num : 1;
            }
        }
    }
    largv = 0;
    if (totfiles) {
        largv = xmalloc (sizeof*largv * (totfiles + 1));
    }
    filesgotten = 0;
    if (largv != 0) {
        int len;
        /* All bits set to zero may not be a NULL ptr */
        for (i=totfiles;  --i>=0;  ) {
            largv[i] = 0;
        }
        largv[totfiles] = 0;

        wait_and_protect_globs ();

        /*--- getcwd has an OpenVMS extension that allows us to ---*/
        /*--- get back Unix-style path names ---*/
        (void) getcwd (CurWorkingDir, sizeof CurWorkingDir - 1, 0);
        len = strlen (CurWorkingDir);
        if (   len > 0 && CurWorkingDir[len-1] != '/') {
            (void) strcat (CurWorkingDir, "/");
        }
        CurArg = 0;
        ArgvList = largv;
        MaxArgs = totfiles + 1;

        for (i=0;  i<argc;  ++i) {
            char *arg = argv[i];

            if (arg != 0 && (   strchr(arg,' ') != 0
                             || strcmp(arg,".") == 0
                             || strcmp(arg,"..") == 0) ) {
                if (CurArg < MaxArgs) {
                    ArgvList[CurArg++] = xstrdup(arg);
                }
                ++filesgotten;
            }else if (arg != 0) {
                char *p = arg;
                int num;
                /* Handle comma-separated filelists */
                while ( (p=strchr(p,',')) != 0) {
                    *p = '\0';
                    num = decc$from_vms (arg, ew_add_file, 1);
                    if (num <= 0 && CurArg < MaxArgs) {
                        ArgvList[CurArg++] = xstrdup(arg);
                    }
                    filesgotten += num>0 ? num : 1;
                    *p++ = ',';
                    arg = p;
                }
                if (*arg != '\0') {
                    num = decc$from_vms (arg, ew_add_file, 1);
                    if (num <= 0 && CurArg < MaxArgs) {
                        ArgvList[CurArg++] = xstrdup(arg);
                    }
                    filesgotten += num>0 ? num : 1;
                }
            }
        }
        if (filesgotten != totfiles) {
            /*--- Files must have been created/deleted here ---*/;
        }
        filesgotten = CurArg;

        release_globs();
    }
    if (!largv) {
        (*pargv) = xmalloc (sizeof(char *));
        if ((*pargv) != 0) {
            *(*pargv) = 0;
        }
    }else {
        (*pargv) = largv;
    }
    (*pargc) = largv ? filesgotten : 0;

    return;
}

#endif  /*  __VMS_VER >= 70200000 && __DECC_VER >= 50700000  */
