[thirdparty/cups.git] / cups / file.c

/*
 * "$Id: file.c 6962 2007-09-17 20:35:47Z mike $"
 *
 *   File functions for the Common UNIX Printing System (CUPS).
 *
 *   Since stdio files max out at 256 files on many systems, we have to
 *   write similar functions without this limit.  At the same time, using
 *   our own file functions allows us to provide transparent support of
 *   gzip'd print files, PPD files, etc.
 *
 *   Copyright 2007-2008 by Apple Inc.
 *   Copyright 1997-2007 by Easy Software Products, all rights reserved.
 *
 *   These coded instructions, statements, and computer programs are the
 *   property of Apple Inc. and are protected by Federal copyright
 *   law.  Distribution and use rights are outlined in the file "LICENSE.txt"
 *   which should have been included with this file.  If this file is
 *   file is missing or damaged, see the license at "http://www.cups.org/".
 *
 * Contents:
 *
 *   cupsFileClose()       - Close a CUPS file.
 *   cupsFileCompression() - Return whether a file is compressed.
 *   cupsFileEOF()         - Return the end-of-file status.
 *   cupsFileFind()        - Find a file using the specified path.
 *   cupsFileFlush()       - Flush pending output.
 *   cupsFileGetChar()     - Get a single character from a file.
 *   cupsFileGetConf()     - Get a line from a configuration file...
 *   cupsFileGetLine()     - Get a CR and/or LF-terminated line that may contain
 *                           binary data.
 *   cupsFileGets()        - Get a CR and/or LF-terminated line.
 *   cupsFileLock()        - Temporarily lock access to a file.
 *   cupsFileNumber()      - Return the file descriptor associated with a CUPS
 *                           file.
 *   cupsFileOpen()        - Open a CUPS file.
 *   cupsFileOpenFd()      - Open a CUPS file using a file descriptor.
 *   cupsFilePeekChar()    - Peek at the next character from a file.
 *   cupsFilePrintf()      - Write a formatted string.
 *   cupsFilePutChar()     - Write a character.
 *   cupsFilePuts()        - Write a string.
 *   cupsFileRead()        - Read from a file.
 *   cupsFileRewind()      - Set the current file position to the beginning of
 *                           the file.
 *   cupsFileSeek()        - Seek in a file.
 *   cupsFileStderr()      - Return a CUPS file associated with stderr.
 *   cupsFileStdin()       - Return a CUPS file associated with stdin.
 *   cupsFileStdout()      - Return a CUPS file associated with stdout.
 *   cupsFileTell()        - Return the current file position.
 *   cupsFileUnlock()      - Unlock access to a file.
 *   cupsFileWrite()       - Write to a file.
 *   cups_compress()       - Compress a buffer of data...
 *   cups_fill()           - Fill the input buffer...
 *   cups_read()           - Read from a file descriptor.
 *   cups_write()          - Write to a file descriptor.
 */

/*
 * Include necessary headers...
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>
#include "http-private.h"
#include "globals.h"
#include "debug.h"

#ifdef HAVE_LIBZ
#  include <zlib.h>
#endif /* HAVE_LIBZ */
#ifdef WIN32
#  include <io.h>
#  include <sys/locking.h>
#endif /* WIN32 */


/*
 * Some operating systems support large files via open flag O_LARGEFILE...
 */

#ifndef O_LARGEFILE
#  define O_LARGEFILE 0
#endif /* !O_LARGEFILE */


/*
 * Some operating systems don't define O_BINARY, which is used by Microsoft
 * and IBM to flag binary files...
 */

#ifndef O_BINARY
#  define O_BINARY 0
#endif /* !O_BINARY */


/*
 * Types and structures...
 */

struct _cups_file_s                     /**** CUPS file structure... ****/

{
  int           fd;                     /* File descriptor */
  char          mode,                   /* Mode ('r' or 'w') */
                compressed,             /* Compression used? */
                is_stdio,               /* stdin/out/err? */
                eof,                    /* End of file? */
                buf[4096],              /* Buffer */
                *ptr,                   /* Pointer into buffer */
                *end;                   /* End of buffer data */
  off_t         pos,                    /* Position in file */
                bufpos;                 /* File position for start of buffer */

#ifdef HAVE_LIBZ
  z_stream      stream;                 /* (De)compression stream */
  Bytef         cbuf[4096];             /* (De)compression buffer */
  uLong         crc;                    /* (De)compression CRC */
#endif /* HAVE_LIBZ */
};


/*
 * Local functions...
 */

#ifdef HAVE_LIBZ
static ssize_t  cups_compress(cups_file_t *fp, const char *buf, size_t bytes);
#endif /* HAVE_LIBZ */
static ssize_t  cups_fill(cups_file_t *fp);
static ssize_t  cups_read(cups_file_t *fp, char *buf, size_t bytes);
static ssize_t  cups_write(cups_file_t *fp, const char *buf, size_t bytes);


/*
 * 'cupsFileClose()' - Close a CUPS file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 0 on success, -1 on error */
cupsFileClose(cups_file_t *fp)          /* I - CUPS file */
{
  int   fd;                             /* File descriptor */
  char  mode;                           /* Open mode */
  int   status;                         /* Return status */
  int   is_stdio;                       /* Is a stdio file? */


  DEBUG_printf(("cupsFileClose(fp=%p)\n", fp));

 /*
  * Range check...
  */

  if (!fp)
    return (-1);

 /*
  * Flush pending write data...
  */

  if (fp->mode == 'w')
    status = cupsFileFlush(fp);
  else
    status = 0;

#ifdef HAVE_LIBZ
  if (fp->compressed && status >= 0)
  {
    if (fp->mode == 'r')
    {
     /*
      * Free decompression data...
      */

      inflateEnd(&fp->stream);
    }
    else
    {
     /*
      * Flush any remaining compressed data...
      */

      unsigned char     trailer[8];     /* Trailer CRC and length */
      int               done;           /* Done writing... */


      fp->stream.avail_in = 0;

      for (done = 0;;)
      {
        if (fp->stream.next_out > fp->cbuf)
        {
          if (cups_write(fp, (char *)fp->cbuf,
                         fp->stream.next_out - fp->cbuf) < 0)
            status = -1;

          fp->stream.next_out  = fp->cbuf;
          fp->stream.avail_out = sizeof(fp->cbuf);
        }

        if (done || status < 0)
          break;

        done = deflate(&fp->stream, Z_FINISH) == Z_STREAM_END &&
               fp->stream.next_out == fp->cbuf;
      }

     /*
      * Write the CRC and length...
      */

      trailer[0] = fp->crc;
      trailer[1] = fp->crc >> 8;
      trailer[2] = fp->crc >> 16;
      trailer[3] = fp->crc >> 24;
      trailer[4] = fp->pos;
      trailer[5] = fp->pos >> 8;
      trailer[6] = fp->pos >> 16;
      trailer[7] = fp->pos >> 24;

      if (cups_write(fp, (char *)trailer, 8) < 0)
        status = -1;

     /*
      * Free all memory used by the compression stream...
      */

      deflateEnd(&(fp->stream));
    }
  }
#endif /* HAVE_LIBZ */

 /*
  * Save the file descriptor we used and free memory...
  */

  fd       = fp->fd;
  mode     = fp->mode;
  is_stdio = fp->is_stdio;

  free(fp);

 /*
  * Close the file, returning the close status...
  */

  if (mode == 's')
  {
    if (closesocket(fd) < 0)
      status = -1;
  }
  else if (!is_stdio)
  {
    if (close(fd) < 0)
      status = -1;
  }

  return (status);
}


/*
 * 'cupsFileCompression()' - Return whether a file is compressed.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - @code CUPS_FILE_NONE@ or @code CUPS_FILE_GZIP@ */
cupsFileCompression(cups_file_t *fp)    /* I - CUPS file */
{
  return (fp ? fp->compressed : CUPS_FILE_NONE);
}


/*
 * 'cupsFileEOF()' - Return the end-of-file status.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 1 on end of file, 0 otherwise */
cupsFileEOF(cups_file_t *fp)            /* I - CUPS file */
{
  return (fp ? fp->eof : 1);
}


/*
 * 'cupsFileFind()' - Find a file using the specified path.
 *
 * This function allows the paths in the path string to be separated by
 * colons (UNIX standard) or semicolons (Windows standard) and stores the
 * result in the buffer supplied.  If the file cannot be found in any of
 * the supplied paths, @code NULL@ is returned. A @code NULL@ path only
 * matches the current directory.
 *
 * @since CUPS 1.2@
 */

const char *                            /* O - Full path to file or @code NULL@ if not found */
cupsFileFind(const char *filename,      /* I - File to find */
             const char *path,          /* I - Colon/semicolon-separated path */
             int        executable,     /* I - 1 = executable files, 0 = any file/dir */
             char       *buffer,        /* I - Filename buffer */
             int        bufsize)        /* I - Size of filename buffer */
{
  char  *bufptr,                        /* Current position in buffer */
        *bufend;                        /* End of buffer */


 /*
  * Range check input...
  */

  if (!filename || !buffer || bufsize < 2)
    return (NULL);

  if (!path)
  {
   /*
    * No path, so check current directory...
    */

    if (!access(filename, 0))
    {
      strlcpy(buffer, filename, bufsize);
      return (buffer);
    }
    else
      return (NULL);
  }

 /*
  * Now check each path and return the first match...
  */

  bufend = buffer + bufsize - 1;
  bufptr = buffer;

  while (*path)
  {
#ifdef WIN32
    if (*path == ';' || (*path == ':' && ((bufptr - buffer) > 1 || !isalpha(buffer[0] & 255))))
#else
    if (*path == ';' || *path == ':')
#endif /* WIN32 */
    {
      if (bufptr > buffer && bufptr[-1] != '/' && bufptr < bufend)
        *bufptr++ = '/';

      strlcpy(bufptr, filename, bufend - bufptr);

#ifdef WIN32
      if (!access(buffer, 0))
#else
      if (!access(buffer, executable ? X_OK : 0))
#endif /* WIN32 */
      {
        DEBUG_printf(("cupsFileFind: Returning \"%s\"\n", buffer));
        return (buffer);
      }

      bufptr = buffer;
    }
    else if (bufptr < bufend)
      *bufptr++ = *path;

    path ++;
  }

 /*
  * Check the last path...
  */

  if (bufptr > buffer && bufptr[-1] != '/' && bufptr < bufend)
    *bufptr++ = '/';

  strlcpy(bufptr, filename, bufend - bufptr);

  if (!access(buffer, 0))
  {
    DEBUG_printf(("cupsFileFind: Returning \"%s\"\n", buffer));
    return (buffer);
  }
  else
  {
    DEBUG_puts("cupsFileFind: Returning NULL");
    return (NULL);
  }
}


/*
 * 'cupsFileFlush()' - Flush pending output.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 0 on success, -1 on error */
cupsFileFlush(cups_file_t *fp)          /* I - CUPS file */
{
  ssize_t       bytes;                  /* Bytes to write */


  DEBUG_printf(("cupsFileFlush(fp=%p)\n", fp));

 /*
  * Range check input...
  */

  if (!fp || fp->mode != 'w')
  {
    DEBUG_puts("cupsFileFlush: Attempt to flush a read-only file...");
    return (-1);
  }

  bytes = (ssize_t)(fp->ptr - fp->buf);

  DEBUG_printf(("cupsFileFlush: Flushing " CUPS_LLFMT " bytes...\n",
                CUPS_LLCAST bytes));

  if (bytes > 0)
  {
#ifdef HAVE_LIBZ
    if (fp->compressed)
      bytes = cups_compress(fp, fp->buf, bytes);
    else
#endif /* HAVE_LIBZ */
      bytes = cups_write(fp, fp->buf, bytes);

    if (bytes < 0)
      return (-1);

    fp->ptr = fp->buf;
  }
   
  return (0);
}


/*
 * 'cupsFileGetChar()' - Get a single character from a file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - Character or -1 on end of file */
cupsFileGetChar(cups_file_t *fp)        /* I - CUPS file */
{
 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileGetChar(fp=%p)\n", fp));

  if (!fp || (fp->mode != 'r' && fp->mode != 's'))
  {
    DEBUG_puts("cupsFileGetChar: Bad arguments!");
    return (-1);
  }

 /*
  * If the input buffer is empty, try to read more data...
  */

  if (fp->ptr >= fp->end)
    if (cups_fill(fp) < 0)
    {
      DEBUG_puts("cupsFileGetChar: Unable to fill buffer!");
      return (-1);
    }

 /*
  * Return the next character in the buffer...
  */

  DEBUG_printf(("cupsFileGetChar: Returning %d...\n", *(fp->ptr) & 255));

  fp->pos ++;

  DEBUG_printf(("cupsFileGetChar: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (*(fp->ptr)++ & 255);
}


/*
 * 'cupsFileGetConf()' - Get a line from a configuration file...
 *
 * @since CUPS 1.2@
 */

char *                                  /* O  - Line read or @code NULL@ on end of file or error */
cupsFileGetConf(cups_file_t *fp,        /* I  - CUPS file */
                char        *buf,       /* O  - String buffer */
                size_t      buflen,     /* I  - Size of string buffer */
                char        **value,    /* O  - Pointer to value */
                int         *linenum)   /* IO - Current line number */
{
  char  *ptr;                           /* Pointer into line */


 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileGetConf(fp=%p, buf=%p, buflen=" CUPS_LLFMT
                ", value=%p, linenum=%p)\n", fp, buf, CUPS_LLCAST buflen,
                value, linenum));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') ||
      !buf || buflen < 2 || !value)
  {
    if (value)
      *value = NULL;

    return (NULL);
  }

 /*
  * Read the next non-comment line...
  */

  *value = NULL;

  while (cupsFileGets(fp, buf, buflen))
  {
    (*linenum) ++;

   /*
    * Strip any comments...
    */

    if ((ptr = strchr(buf, '#')) != NULL)
    {
      if (ptr > buf && ptr[-1] == '\\')
      {
        // Unquote the #...
        _cups_strcpy(ptr - 1, ptr);
      }
      else
      {
        // Strip the comment and any trailing whitespace...
        while (ptr > buf)
        {
          if (!isspace(ptr[-1] & 255))
            break;

          ptr --;
        }

        *ptr = '\0';
      }
    }

   /*
    * Strip leading whitespace...
    */

    for (ptr = buf; isspace(*ptr & 255); ptr ++);

    if (ptr > buf)
      _cups_strcpy(buf, ptr);

   /*
    * See if there is anything left...
    */

    if (buf[0])
    {
     /*
      * Yes, grab any value and return...
      */

      for (ptr = buf; *ptr; ptr ++)
        if (isspace(*ptr & 255))
          break;

      if (*ptr)
      {
       /*
        * Have a value, skip any other spaces...
        */

        while (isspace(*ptr & 255))
          *ptr++ = '\0';

        if (*ptr)
          *value = ptr;

       /*
        * Strip trailing whitespace and > for lines that begin with <...
        */

        ptr += strlen(ptr) - 1;

        if (buf[0] == '<' && *ptr == '>')
          *ptr-- = '\0';
        else if (buf[0] == '<' && *ptr != '>')
        {
         /*
          * Syntax error...
          */

          *value = NULL;
          return (buf);
        }

        while (ptr > *value && isspace(*ptr & 255))
          *ptr-- = '\0';
      }

     /*
      * Return the line...
      */

      return (buf);
    }
  }

  return (NULL);
}


/*
 * 'cupsFileGetLine()' - Get a CR and/or LF-terminated line that may
 *                       contain binary data.
 *
 * This function differs from @link cupsFileGets@ in that the trailing CR
 * and LF are preserved, as is any binary data on the line. The buffer is
 * nul-terminated, however you should use the returned length to determine
 * the number of bytes on the line.
 *
 * @since CUPS 1.2@
 */

size_t                                  /* O - Number of bytes on line or 0 on end of file */
cupsFileGetLine(cups_file_t *fp,        /* I - File to read from */
                char        *buf,       /* I - Buffer */
                size_t      buflen)     /* I - Size of buffer */
{
  int           ch;                     /* Character from file */
  char          *ptr,                   /* Current position in line buffer */
                *end;                   /* End of line buffer */


 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileGetLine(fp=%p, buf=%p, buflen=" CUPS_LLFMT ")\n",
                fp, buf, CUPS_LLCAST buflen));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') || !buf || buflen < 3)
    return (0);

 /*
  * Now loop until we have a valid line...
  */

  for (ptr = buf, end = buf + buflen - 2; ptr < end ;)
  {
    if (fp->ptr >= fp->end)
      if (cups_fill(fp) <= 0)
        break;

    *ptr++ = ch = *(fp->ptr)++;
    fp->pos ++;

    if (ch == '\r')
    {
     /*
      * Check for CR LF...
      */

      if (fp->ptr >= fp->end)
        if (cups_fill(fp) <= 0)
          break;

      if (*(fp->ptr) == '\n')
      {
        *ptr++ = *(fp->ptr)++;
        fp->pos ++;
      }

      break;
    }
    else if (ch == '\n')
    {
     /*
      * Line feed ends a line...
      */

      break;
    }
  }

  *ptr = '\0';

  DEBUG_printf(("cupsFileGetLine: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (ptr - buf);
}


/*
 * 'cupsFileGets()' - Get a CR and/or LF-terminated line.
 *
 * @since CUPS 1.2@
 */

char *                                  /* O - Line read or @code NULL@ on end of file or error */
cupsFileGets(cups_file_t *fp,           /* I - CUPS file */
             char        *buf,          /* O - String buffer */
             size_t      buflen)        /* I - Size of string buffer */
{
  int           ch;                     /* Character from file */
  char          *ptr,                   /* Current position in line buffer */
                *end;                   /* End of line buffer */


 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileGets(fp=%p, buf=%p, buflen=" CUPS_LLFMT ")\n", fp, buf,
                CUPS_LLCAST buflen));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') || !buf || buflen < 2)
    return (NULL);

 /*
  * Now loop until we have a valid line...
  */

  for (ptr = buf, end = buf + buflen - 1; ptr < end ;)
  {
    if (fp->ptr >= fp->end)
      if (cups_fill(fp) <= 0)
      {
        if (ptr == buf)
          return (NULL);
        else
          break;
      }

    ch = *(fp->ptr)++;
    fp->pos ++;

    if (ch == '\r')
    {
     /*
      * Check for CR LF...
      */

      if (fp->ptr >= fp->end)
        if (cups_fill(fp) <= 0)
          break;

      if (*(fp->ptr) == '\n')
      {
        fp->ptr ++;
        fp->pos ++;
      }

      break;
    }
    else if (ch == '\n')
    {
     /*
      * Line feed ends a line...
      */

      break;
    }
    else
      *ptr++ = ch;
  }

  *ptr = '\0';

  DEBUG_printf(("cupsFileGets: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (buf);
}


/*
 * 'cupsFileLock()' - Temporarily lock access to a file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 0 on success, -1 on error */
cupsFileLock(cups_file_t *fp,           /* I - CUPS file */
             int         block)         /* I - 1 to wait for the lock, 0 to fail right away */
{
 /*
  * Range check...
  */

  if (!fp || fp->mode == 's')
    return (-1);

 /*
  * Try the lock...
  */

#ifdef WIN32
  return (locking(fp->fd, block ? _LK_LOCK : _LK_NBLCK, 0));
#else
  return (lockf(fp->fd, block ? F_LOCK : F_TLOCK, 0));
#endif /* WIN32 */
}


/*
 * 'cupsFileNumber()' - Return the file descriptor associated with a CUPS file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - File descriptor */
cupsFileNumber(cups_file_t *fp)         /* I - CUPS file */
{
  if (fp)
    return (fp->fd);
  else
    return (-1);
}


/*
 * 'cupsFileOpen()' - Open a CUPS file.
 *
 * The "mode" parameter can be "r" to read, "w" to write, overwriting any
 * existing file, "a" to append to an existing file or create a new file,
 * or "s" to open a socket connection.
 *
 * When opening for writing ("w"), an optional number from 1 to 9 can be
 * supplied which enables Flate compression of the file.  Compression is
 * not supported for the "a" (append) mode.
 *
 * When opening a socket connection, the filename is a string of the form
 * "address:port" or "hostname:port". The socket will make an IPv4 or IPv6
 * connection as needed, generally preferring IPv6 connections when there is
 * a choice.
 *
 * @since CUPS 1.2@
 */

cups_file_t *                           /* O - CUPS file or @code NULL@ if the file or socket cannot be opened */
cupsFileOpen(const char *filename,      /* I - Name of file */
             const char *mode)          /* I - Open mode */
{
  cups_file_t   *fp;                    /* New CUPS file */
  int           fd;                     /* File descriptor */
  char          hostname[1024],         /* Hostname */
                *portname;              /* Port "name" (number or service) */
  http_addrlist_t *addrlist;            /* Host address list */


  DEBUG_printf(("cupsFileOpen(filename=\"%s\", mode=\"%s\")\n", filename,
                mode));

 /*
  * Range check input...
  */

  if (!filename || !mode ||
      (*mode != 'r' && *mode != 'w' && *mode != 'a' && *mode != 's') ||
      (*mode == 'a' && isdigit(mode[1] & 255)))
    return (NULL);

 /*
  * Open the file...
  */

  switch (*mode)
  {
    case 'a' : /* Append file */
        fd = open(filename, O_RDWR | O_CREAT | O_APPEND | O_LARGEFILE | O_BINARY, 0666);
        break;

    case 'r' : /* Read file */
        fd = open(filename, O_RDONLY | O_LARGEFILE | O_BINARY, 0);
        break;

    case 'w' : /* Write file */
        fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT | O_LARGEFILE | O_BINARY, 0666);
        break;

    case 's' : /* Read/write socket */
        strlcpy(hostname, filename, sizeof(hostname));
        if ((portname = strrchr(hostname, ':')) != NULL)
          *portname++ = '\0';
        else
          return (NULL);

       /*
        * Lookup the hostname and service...
        */

        if ((addrlist = httpAddrGetList(hostname, AF_UNSPEC, portname)) == NULL)
          return (NULL);

       /*
        * Connect to the server...
        */

        if (!httpAddrConnect(addrlist, &fd))
        {
          httpAddrFreeList(addrlist);
          return (NULL);
        }

        httpAddrFreeList(addrlist);
        break;

    default : /* Remove bogus compiler warning... */
        return (NULL);
  }

  if (fd < 0)
    return (NULL);

 /*
  * Create the CUPS file structure...
  */

  if ((fp = cupsFileOpenFd(fd, mode)) == NULL)
  {
    if (*mode == 's')
      closesocket(fd);
    else
      close(fd);
  }

 /*
  * Return it...
  */

  return (fp);
}

/*
 * 'cupsFileOpenFd()' - Open a CUPS file using a file descriptor.
 *
 * The "mode" parameter can be "r" to read, "w" to write, "a" to append,
 * or "s" to treat the file descriptor as a bidirectional socket connection.
 *
 * When opening for writing ("w"), an optional number from 1 to 9 can be
 * supplied which enables Flate compression of the file.  Compression is
 * not supported for the "a" (append) mode.
 *
 * @since CUPS 1.2@
 */

cups_file_t *                           /* O - CUPS file or @code NULL@ if the file could not be opened */
cupsFileOpenFd(int        fd,           /* I - File descriptor */
               const char *mode)        /* I - Open mode */
{
  cups_file_t   *fp;                    /* New CUPS file */


  DEBUG_printf(("cupsFileOpenFd(fd=%d, mode=\"%s\")\n", fd, mode));

 /*
  * Range check input...
  */

  if (fd < 0 || !mode ||
      (*mode != 'r' && *mode != 'w' && *mode != 'a' && *mode != 's') ||
      (*mode == 'a' && isdigit(mode[1] & 255)))
    return (NULL);

 /*
  * Allocate memory...
  */

  if ((fp = calloc(1, sizeof(cups_file_t))) == NULL)
    return (NULL);

 /*
  * Open the file...
  */

  fp->fd = fd;

  switch (*mode)
  {
    case 'a' :
        fp->pos = lseek(fd, 0, SEEK_END);

    case 'w' :
        fp->mode = 'w';
        fp->ptr  = fp->buf;
        fp->end  = fp->buf + sizeof(fp->buf);

#ifdef HAVE_LIBZ
        if (mode[1] >= '1' && mode[1] <= '9')
        {
         /*
          * Open a compressed stream, so write the standard gzip file
          * header...
          */

          unsigned char header[10];     /* gzip file header */
          time_t        curtime;        /* Current time */


          curtime   = time(NULL);
          header[0] = 0x1f;
          header[1] = 0x8b;
          header[2] = Z_DEFLATED;
          header[3] = 0;
          header[4] = curtime;
          header[5] = curtime >> 8;
          header[6] = curtime >> 16;
          header[7] = curtime >> 24;
          header[8] = 0;
          header[9] = 0x03;

          cups_write(fp, (char *)header, 10);

         /*
          * Initialize the compressor...
          */

          deflateInit2(&(fp->stream), mode[1] - '0', Z_DEFLATED, -15, 8,
                       Z_DEFAULT_STRATEGY);

          fp->stream.next_out  = fp->cbuf;
          fp->stream.avail_out = sizeof(fp->cbuf);
          fp->compressed       = 1;
          fp->crc              = crc32(0L, Z_NULL, 0);
        }
#endif /* HAVE_LIBZ */
        break;

    case 'r' :
        fp->mode = 'r';
        break;

    case 's' :
        fp->mode = 's';
        break;

    default : /* Remove bogus compiler warning... */
        return (NULL);
  }

 /*
  * Don't pass this file to child processes...
  */

#ifndef WIN32
  fcntl(fp->fd, F_SETFD, fcntl(fp->fd, F_GETFD) | FD_CLOEXEC);
#endif /* !WIN32 */

  return (fp);
}


/*
 * 'cupsFilePeekChar()' - Peek at the next character from a file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - Character or -1 on end of file */
cupsFilePeekChar(cups_file_t *fp)       /* I - CUPS file */
{
 /*
  * Range check input...
  */

  if (!fp || (fp->mode != 'r' && fp->mode != 's'))
    return (-1);

 /*
  * If the input buffer is empty, try to read more data...
  */

  if (fp->ptr >= fp->end)
    if (cups_fill(fp) < 0)
      return (-1);

 /*
  * Return the next character in the buffer...
  */

  return (*(fp->ptr) & 255);
}


/*
 * 'cupsFilePrintf()' - Write a formatted string.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - Number of bytes written or -1 on error */
cupsFilePrintf(cups_file_t *fp,         /* I - CUPS file */
               const char  *format,     /* I - Printf-style format string */
               ...)                     /* I - Additional args as necessary */
{
  va_list       ap;                     /* Argument list */
  ssize_t       bytes;                  /* Formatted size */
  char          buf[8192];              /* Formatted text */


  DEBUG_printf(("cupsFilePrintf(fp=%p, format=\"%s\", ...)\n", fp, format));

  if (!fp || !format || (fp->mode != 'w' && fp->mode != 's'))
    return (-1);

  va_start(ap, format);
  bytes = vsnprintf(buf, sizeof(buf), format, ap);
  va_end(ap);

  if (bytes >= sizeof(buf))
    return (-1);

  if (fp->mode == 's')
  {
    if (cups_write(fp, buf, bytes) < 0)
      return (-1);

    fp->pos += bytes;

    DEBUG_printf(("cupsFilePrintf: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

    return (bytes);
  }

  if ((fp->ptr + bytes) > fp->end)
    if (cupsFileFlush(fp))
      return (-1);

  fp->pos += bytes;

  DEBUG_printf(("cupsFilePrintf: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  if (bytes > sizeof(fp->buf))
  {
#ifdef HAVE_LIBZ
    if (fp->compressed)
      return (cups_compress(fp, buf, bytes));
    else
#endif /* HAVE_LIBZ */
      return (cups_write(fp, buf, bytes));
  }
  else
  {
    memcpy(fp->ptr, buf, bytes);
    fp->ptr += bytes;
    return (bytes);
  }
}


/*
 * 'cupsFilePutChar()' - Write a character.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 0 on success, -1 on error */
cupsFilePutChar(cups_file_t *fp,        /* I - CUPS file */
                int         c)          /* I - Character to write */
{
 /*
  * Range check input...
  */

  if (!fp || (fp->mode != 'w' && fp->mode != 's'))
    return (-1);

  if (fp->mode == 's')
  {
   /*
    * Send character immediately over socket...
    */

    char ch;                            /* Output character */


    ch = c;

    if (send(fp->fd, &ch, 1, 0) < 1)
      return (-1);
  }
  else
  {
   /*
    * Buffer it up...
    */

    if (fp->ptr >= fp->end)
      if (cupsFileFlush(fp))
        return (-1);

    *(fp->ptr) ++ = c;
  }

  fp->pos ++;

  DEBUG_printf(("cupsFilePutChar: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (0);
}


/*
 * 'cupsFilePuts()' - Write a string.
 *
 * Like the @code fputs@ function, no newline is appended to the string.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - Number of bytes written or -1 on error */
cupsFilePuts(cups_file_t *fp,           /* I - CUPS file */
             const char  *s)            /* I - String to write */
{
  ssize_t       bytes;                  /* Bytes to write */


 /*
  * Range check input...
  */

  if (!fp || !s || (fp->mode != 'w' && fp->mode != 's'))
    return (-1);

 /*
  * Write the string...
  */

  bytes = (int)strlen(s);

  if (fp->mode == 's')
  {
    if (cups_write(fp, s, bytes) < 0)
      return (-1);

    fp->pos += bytes;

    DEBUG_printf(("cupsFilePuts: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

    return (bytes);
  }

  if ((fp->ptr + bytes) > fp->end)
    if (cupsFileFlush(fp))
      return (-1);

  fp->pos += bytes;

  DEBUG_printf(("cupsFilePuts: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  if (bytes > sizeof(fp->buf))
  {
#ifdef HAVE_LIBZ
    if (fp->compressed)
      return (cups_compress(fp, s, bytes));
    else
#endif /* HAVE_LIBZ */
      return (cups_write(fp, s, bytes));
  }
  else
  {
    memcpy(fp->ptr, s, bytes);
    fp->ptr += bytes;
    return (bytes);
  }
}


/*
 * 'cupsFileRead()' - Read from a file.
 *
 * @since CUPS 1.2@
 */

ssize_t                                 /* O - Number of bytes read or -1 on error */
cupsFileRead(cups_file_t *fp,           /* I - CUPS file */
             char        *buf,          /* O - Buffer */
             size_t      bytes)         /* I - Number of bytes to read */
{
  size_t        total;                  /* Total bytes read */
  ssize_t       count;                  /* Bytes read */


  DEBUG_printf(("cupsFileRead(fp=%p, buf=%p, bytes=" CUPS_LLFMT ")\n", fp, buf,
                CUPS_LLCAST bytes));

 /*
  * Range check input...
  */

  if (!fp || !buf || bytes < 0 || (fp->mode != 'r' && fp->mode != 's'))
    return (-1);

  if (bytes == 0)
    return (0);

 /*
  * Loop until all bytes are read...
  */

  total = 0;
  while (bytes > 0)
  {
    if (fp->ptr >= fp->end)
      if (cups_fill(fp) <= 0)
      {
        DEBUG_printf(("cupsFileRead: cups_fill() returned -1, total=" CUPS_LLFMT "\n",
                      CUPS_LLCAST total));

        if (total > 0)
          return ((ssize_t)total);
        else
          return (-1);
      }

    count = (ssize_t)(fp->end - fp->ptr);
    if (count > (ssize_t)bytes)
      count = (ssize_t)bytes;

    memcpy(buf, fp->ptr, count);
    fp->ptr += count;
    fp->pos += count;

    DEBUG_printf(("cupsFileRead: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

   /*
    * Update the counts for the last read...
    */

    bytes -= count;
    total += count;
    buf   += count;
  }

 /*
  * Return the total number of bytes read...
  */

  DEBUG_printf(("cupsFileRead: total=%d\n", (int)total));

  return ((ssize_t)total);
}


/*
 * 'cupsFileRewind()' - Set the current file position to the beginning of the
 *                      file.
 *
 * @since CUPS 1.2@
 */

off_t                                   /* O - New file position or -1 on error */
cupsFileRewind(cups_file_t *fp)         /* I - CUPS file */
{
 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileRewind(fp=%p)\n", fp));
  DEBUG_printf(("cupsFileRewind: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  if (!fp || fp->mode != 'r')
    return (-1);

 /*
  * Handle special cases...
  */

  if (fp->bufpos == 0)
  {
   /*
    * No seeking necessary...
    */

    fp->pos = 0;

    if (fp->ptr)
    {
      fp->ptr = fp->buf;
      fp->eof = 0;
    }

    DEBUG_printf(("cupsFileRewind: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

    return (0);
  }

 /*
  * Otherwise, seek in the file and cleanup any compression buffers...
  */

#ifdef HAVE_LIBZ
  if (fp->compressed)
  {
    inflateEnd(&fp->stream);
    fp->compressed = 0;
  }
#endif /* HAVE_LIBZ */

  if (lseek(fp->fd, 0, SEEK_SET))
  {
    DEBUG_printf(("cupsFileRewind: lseek failed: %s\n", strerror(errno)));
    return (-1);
  }

  fp->bufpos = 0;
  fp->pos    = 0;
  fp->ptr    = NULL;
  fp->end    = NULL;
  fp->eof    = 0;

  DEBUG_printf(("cupsFileRewind: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (0);
}


/*
 * 'cupsFileSeek()' - Seek in a file.
 *
 * @since CUPS 1.2@
 */

off_t                                   /* O - New file position or -1 on error */
cupsFileSeek(cups_file_t *fp,           /* I - CUPS file */
             off_t       pos)           /* I - Position in file */
{
  ssize_t       bytes;                  /* Number bytes in buffer */


  DEBUG_printf(("cupsFileSeek(fp=%p, pos=" CUPS_LLFMT ")\n", fp,
                CUPS_LLCAST pos));
  DEBUG_printf(("cupsFileSeek: fp->pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));
  DEBUG_printf(("cupsFileSeek: fp->ptr=%p, fp->end=%p\n", fp->ptr, fp->end));

 /*
  * Range check input...
  */

  if (!fp || pos < 0 || fp->mode != 'r')
    return (-1);

 /*
  * Handle special cases...
  */

  if (pos == 0)
    return (cupsFileRewind(fp));

  if (fp->ptr)
  {
    bytes = (ssize_t)(fp->end - fp->buf);

    if (pos >= fp->bufpos && pos < (fp->bufpos + bytes))
    {
     /*
      * No seeking necessary...
      */

      fp->pos = pos;
      fp->ptr = fp->buf + pos - fp->bufpos;
      fp->eof = 0;

      return (pos);
    }
  }

#ifdef HAVE_LIBZ
  if (!fp->compressed && !fp->ptr)
  {
   /*
    * Preload a buffer to determine whether the file is compressed...
    */

    if (cups_fill(fp) < 0)
      return (-1);
  }
#endif /* HAVE_LIBZ */

 /*
  * Seek forwards or backwards...
  */

  fp->eof = 0;

  DEBUG_printf(("cupsFileSeek: bytes=" CUPS_LLFMT "\n", CUPS_LLCAST bytes));

  if (pos < fp->bufpos)
  {
   /*
    * Need to seek backwards...
    */

    DEBUG_puts("cupsFileSeek: SEEK BACKWARDS");

#ifdef HAVE_LIBZ
    if (fp->compressed)
    {
      inflateEnd(&fp->stream);

      lseek(fp->fd, 0, SEEK_SET);
      fp->bufpos = 0;
      fp->pos    = 0;
      fp->ptr    = NULL;
      fp->end    = NULL;

      while ((bytes = cups_fill(fp)) > 0)
        if (pos >= fp->bufpos && pos < (fp->bufpos + bytes))
          break;

      if (bytes <= 0)
        return (-1);

      fp->ptr = fp->buf + pos - fp->bufpos;
      fp->pos = pos;
    }
    else
#endif /* HAVE_LIBZ */
    {
      fp->bufpos = lseek(fp->fd, pos, SEEK_SET);
      fp->pos    = fp->bufpos;
      fp->ptr    = NULL;
      fp->end    = NULL;

      DEBUG_printf(("cupsFileSeek: lseek() returned " CUPS_LLFMT "...\n",
                    CUPS_LLCAST fp->pos));
    }
  }
  else
  {
   /*
    * Need to seek forwards...
    */

    DEBUG_puts("cupsFileSeek: SEEK FORWARDS");

#ifdef HAVE_LIBZ
    if (fp->compressed)
    {
      while ((bytes = cups_fill(fp)) > 0)
      {
        if (pos >= fp->bufpos && pos < (fp->bufpos + bytes))
          break;
      }

      if (bytes <= 0)
        return (-1);

      fp->ptr = fp->buf + pos - fp->bufpos;
      fp->pos = pos;
    }
    else
#endif /* HAVE_LIBZ */
    {
      fp->bufpos = lseek(fp->fd, pos, SEEK_SET);
      fp->pos    = fp->bufpos;
      fp->ptr    = NULL;
      fp->end    = NULL;

      DEBUG_printf(("cupsFileSeek: lseek() returned " CUPS_LLFMT "...\n",
                    CUPS_LLCAST fp->pos));
    }
  }

  DEBUG_printf(("cupsFileSeek: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  return (fp->pos);
}


/*
 * 'cupsFileStderr()' - Return a CUPS file associated with stderr.
 *
 * @since CUPS 1.2@
 */

cups_file_t *                           /* O - CUPS file */
cupsFileStderr(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals... */


 /*
  * Open file descriptor 2 as needed...
  */

  if (!cg->stdio_files[2])
  {
   /*
    * Flush any pending output on the stdio file...
    */

    fflush(stderr);

   /*
    * Open file descriptor 2...
    */

    if ((cg->stdio_files[2] = cupsFileOpenFd(2, "w")) != NULL)
      cg->stdio_files[2]->is_stdio = 1;
  }

  return (cg->stdio_files[2]);
}


/*
 * 'cupsFileStdin()' - Return a CUPS file associated with stdin.
 *
 * @since CUPS 1.2@
 */

cups_file_t *                           /* O - CUPS file */
cupsFileStdin(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals... */


 /*
  * Open file descriptor 0 as needed...
  */

  if (!cg->stdio_files[0])
  {
   /*
    * Open file descriptor 0...
    */

    if ((cg->stdio_files[0] = cupsFileOpenFd(0, "r")) != NULL)
      cg->stdio_files[0]->is_stdio = 1;
  }

  return (cg->stdio_files[0]);
}


/*
 * 'cupsFileStdout()' - Return a CUPS file associated with stdout.
 *
 * @since CUPS 1.2@
 */

cups_file_t *                           /* O - CUPS file */
cupsFileStdout(void)
{
  _cups_globals_t *cg = _cupsGlobals(); /* Pointer to library globals... */


 /*
  * Open file descriptor 1 as needed...
  */

  if (!cg->stdio_files[1])
  {
   /*
    * Flush any pending output on the stdio file...
    */

    fflush(stdout);

   /*
    * Open file descriptor 1...
    */

    if ((cg->stdio_files[1] = cupsFileOpenFd(1, "w")) != NULL)
      cg->stdio_files[1]->is_stdio = 1;
  }

  return (cg->stdio_files[1]);
}


/*
 * 'cupsFileTell()' - Return the current file position.
 *
 * @since CUPS 1.2@
 */

off_t                                   /* O - File position */
cupsFileTell(cups_file_t *fp)           /* I - CUPS file */
{
  DEBUG_printf(("cupsFileTell(fp=%p)\n", fp));
  DEBUG_printf(("cupsFileTell: pos=" CUPS_LLFMT "\n", CUPS_LLCAST (fp ? fp->pos : -1)));

  return (fp ? fp->pos : 0);
}


/*
 * 'cupsFileUnlock()' - Unlock access to a file.
 *
 * @since CUPS 1.2@
 */

int                                     /* O - 0 on success, -1 on error */
cupsFileUnlock(cups_file_t *fp)         /* I - CUPS file */
{
 /*
  * Range check...
  */

  DEBUG_printf(("cupsFileUnlock(fp=%p)\n", fp));

  if (!fp || fp->mode == 's')
    return (-1);

 /*
  * Unlock...
  */

#ifdef WIN32
  return (locking(fp->fd, _LK_UNLCK, 0));
#else
  return (lockf(fp->fd, F_ULOCK, 0));
#endif /* WIN32 */
}


/*
 * 'cupsFileWrite()' - Write to a file.
 *
 * @since CUPS 1.2@
 */

ssize_t                                 /* O - Number of bytes written or -1 on error */
cupsFileWrite(cups_file_t *fp,          /* I - CUPS file */
              const char  *buf,         /* I - Buffer */
              size_t      bytes)        /* I - Number of bytes to write */
{
 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileWrite(fp=%p, buf=%p, bytes=" CUPS_LLFMT ")\n",
                fp, buf, CUPS_LLCAST bytes));

  if (!fp || !buf || bytes < 0 || (fp->mode != 'w' && fp->mode != 's'))
    return (-1);

  if (bytes == 0)
    return (0);

 /*
  * Write the buffer...
  */

  if (fp->mode == 's')
  {
    if (cups_write(fp, buf, bytes) < 0)
      return (-1);

    fp->pos += (off_t)bytes;

    DEBUG_printf(("cupsFileWrite: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

    return ((ssize_t)bytes);
  }

  if ((fp->ptr + bytes) > fp->end)
    if (cupsFileFlush(fp))
      return (-1);

  fp->pos += (off_t)bytes;

  DEBUG_printf(("cupsFileWrite: pos=" CUPS_LLFMT "\n", CUPS_LLCAST fp->pos));

  if (bytes > sizeof(fp->buf))
  {
#ifdef HAVE_LIBZ
    if (fp->compressed)
      return (cups_compress(fp, buf, bytes));
    else
#endif /* HAVE_LIBZ */
      return (cups_write(fp, buf, bytes));
  }
  else
  {
    memcpy(fp->ptr, buf, bytes);
    fp->ptr += bytes;
    return ((ssize_t)bytes);
  }
}


#ifdef HAVE_LIBZ
/*
 * 'cups_compress()' - Compress a buffer of data...
 */

static ssize_t                          /* O - Number of bytes written or -1 */
cups_compress(cups_file_t *fp,          /* I - CUPS file */
              const char  *buf,         /* I - Buffer */
              size_t      bytes)        /* I - Number bytes */
{
  DEBUG_printf(("cups_compress(fp=%p, buf=%p, bytes=" CUPS_LLFMT "\n", fp, buf,
                CUPS_LLCAST bytes));

 /*
  * Update the CRC...
  */

  fp->crc = crc32(fp->crc, (const Bytef *)buf, bytes);

 /*
  * Deflate the bytes...
  */

  fp->stream.next_in  = (Bytef *)buf;
  fp->stream.avail_in = bytes;

  while (fp->stream.avail_in > 0)
  {
   /*
    * Flush the current buffer...
    */

    DEBUG_printf(("cups_compress: avail_in=%d, avail_out=%d\n",
                  fp->stream.avail_in, fp->stream.avail_out));

    if (fp->stream.avail_out < (int)(sizeof(fp->cbuf) / 8))
    {
      if (cups_write(fp, (char *)fp->cbuf, fp->stream.next_out - fp->cbuf) < 0)
        return (-1);

      fp->stream.next_out  = fp->cbuf;
      fp->stream.avail_out = sizeof(fp->cbuf);
    }

    deflate(&(fp->stream), Z_NO_FLUSH);
  }

  return (bytes);
}
#endif /* HAVE_LIBZ */


/*
 * 'cups_fill()' - Fill the input buffer...
 */

static ssize_t                          /* O - Number of bytes or -1 */
cups_fill(cups_file_t *fp)              /* I - CUPS file */
{
  ssize_t               bytes;          /* Number of bytes read */
#ifdef HAVE_LIBZ
  int                   status;         /* Decompression status */
  const unsigned char   *ptr,           /* Pointer into buffer */
                        *end;           /* End of buffer */
#endif /* HAVE_LIBZ */


  DEBUG_printf(("cups_fill(fp=%p)\n", fp));
  DEBUG_printf(("cups_fill: fp->ptr=%p, fp->end=%p, fp->buf=%p, "
                "fp->bufpos=" CUPS_LLFMT ", fp->eof=%d\n",
                fp->ptr, fp->end, fp->buf, CUPS_LLCAST fp->bufpos, fp->eof));

  if (fp->ptr && fp->end)
    fp->bufpos += fp->end - fp->buf;

#ifdef HAVE_LIBZ
  DEBUG_printf(("cups_fill: fp->compressed=%d\n", fp->compressed));

  while (!fp->ptr || fp->compressed)
  {
   /*
    * Check to see if we have read any data yet; if not, see if we have a
    * compressed file...
    */

    if (!fp->ptr)
    {
     /*
      * Reset the file position in case we are seeking...
      */

      fp->compressed = 0;

     /*
      * Read the first bytes in the file to determine if we have a gzip'd
      * file...
      */

      if ((bytes = cups_read(fp, (char *)fp->buf, sizeof(fp->buf))) < 0)
      {
       /*
        * Can't read from file!
        */

        DEBUG_printf(("cups_fill: cups_read() returned " CUPS_LLFMT "!\n",
                      CUPS_LLCAST bytes));

        return (-1);
      }

      if (bytes < 10 || fp->buf[0] != 0x1f ||
          (fp->buf[1] & 255) != 0x8b ||
          fp->buf[2] != 8 || (fp->buf[3] & 0xe0) != 0)
      {
       /*
        * Not a gzip'd file!
        */

        fp->ptr = fp->buf;
        fp->end = fp->buf + bytes;

        DEBUG_printf(("cups_fill: Returning " CUPS_LLFMT "!\n",
                      CUPS_LLCAST bytes));

        return (bytes);
      }

     /*
      * Parse header junk: extra data, original name, and comment...
      */

      ptr = (unsigned char *)fp->buf + 10;
      end = (unsigned char *)fp->buf + bytes;

      if (fp->buf[3] & 0x04)
      {
       /*
        * Skip extra data...
        */

        if ((ptr + 2) > end)
        {
         /*
          * Can't read from file!
          */

          return (-1);
        }

        bytes = ((unsigned char)ptr[1] << 8) | (unsigned char)ptr[0];
        ptr   += 2 + bytes;

        if (ptr > end)
        {
         /*
          * Can't read from file!
          */

          return (-1);
        }
      }

      if (fp->buf[3] & 0x08)
      {
       /*
        * Skip original name data...
        */

        while (ptr < end && *ptr)
          ptr ++;

        if (ptr < end)
          ptr ++;
        else
        {
         /*
          * Can't read from file!
          */

          return (-1);
        }
      }

      if (fp->buf[3] & 0x10)
      {
       /*
        * Skip comment data...
        */

        while (ptr < end && *ptr)
          ptr ++;

        if (ptr < end)
          ptr ++;
        else
        {
         /*
          * Can't read from file!
          */

          return (-1);
        }
      }

      if (fp->buf[3] & 0x02)
      {
       /*
        * Skip header CRC data...
        */

        ptr += 2;

        if (ptr > end)
        {
         /*
          * Can't read from file!
          */

          return (-1);
        }
      }

     /*
      * Copy the flate-compressed data to the compression buffer...
      */

      if ((bytes = end - ptr) > 0)
        memcpy(fp->cbuf, ptr, bytes);

     /*
      * Setup the decompressor data...
      */

      fp->stream.zalloc    = (alloc_func)0;
      fp->stream.zfree     = (free_func)0;
      fp->stream.opaque    = (voidpf)0;
      fp->stream.next_in   = (Bytef *)fp->cbuf;
      fp->stream.next_out  = NULL;
      fp->stream.avail_in  = bytes;
      fp->stream.avail_out = 0;
      fp->crc              = crc32(0L, Z_NULL, 0);

      if (inflateInit2(&(fp->stream), -15) != Z_OK)
        return (-1);

      fp->compressed = 1;
    }

    if (fp->compressed)
    {
     /*
      * If we have reached end-of-file, return immediately...
      */

      if (fp->eof)
        return (-1);

     /*
      * Fill the decompression buffer as needed...
      */

      if (fp->stream.avail_in == 0)
      {
        if ((bytes = cups_read(fp, (char *)fp->cbuf, sizeof(fp->cbuf))) <= 0)
          return (-1);

        fp->stream.next_in  = fp->cbuf;
        fp->stream.avail_in = bytes;
      }

     /*
      * Decompress data from the buffer...
      */

      fp->stream.next_out  = (Bytef *)fp->buf;
      fp->stream.avail_out = sizeof(fp->buf);

      status = inflate(&(fp->stream), Z_NO_FLUSH);

      if (fp->stream.next_out > (Bytef *)fp->buf)
        fp->crc = crc32(fp->crc, (Bytef *)fp->buf,
                        fp->stream.next_out - (Bytef *)fp->buf);

      if (status == Z_STREAM_END)
      {
       /*
        * Read the CRC and length...
        */

        unsigned char   trailer[8];     /* Trailer bytes */
        uLong           tcrc;           /* Trailer CRC */


        if (read(fp->fd, trailer, sizeof(trailer)) < sizeof(trailer))
        {
         /*
          * Can't get it, so mark end-of-file...
          */

          fp->eof = 1;
        }
        else
        {
          tcrc = (((((trailer[3] << 8) | trailer[2]) << 8) | trailer[1]) << 8) |
                 trailer[0];

          if (tcrc != fp->crc)
          {
           /*
            * Bad CRC, mark end-of-file...
            */

            DEBUG_printf(("cups_fill: tcrc=%08x, fp->crc=%08x\n",
                          (unsigned int)tcrc, (unsigned int)fp->crc));

            fp->eof = 1;

            return (-1);
          }

         /*
          * Otherwise, reset the compressed flag so that we re-read the
          * file header...
          */

          fp->compressed = 0;
        }
      }

      bytes = sizeof(fp->buf) - fp->stream.avail_out;

     /*
      * Return the decompressed data...
      */

      fp->ptr = fp->buf;
      fp->end = fp->buf + bytes;

      if (bytes)
        return (bytes);
    }
  }
#endif /* HAVE_LIBZ */

 /*
  * Read a buffer's full of data...
  */

  if ((bytes = cups_read(fp, fp->buf, sizeof(fp->buf))) <= 0)
  {
   /*
    * Can't read from file!
    */

    fp->eof = 1;
    fp->ptr = fp->buf;
    fp->end = fp->buf;

    return (-1);
  }

 /*
  * Return the bytes we read...
  */

  fp->eof = 0;
  fp->ptr = fp->buf;
  fp->end = fp->buf + bytes;

  return (bytes);
}


/*
 * 'cups_read()' - Read from a file descriptor.
 */

static ssize_t                          /* O - Number of bytes read or -1 */
cups_read(cups_file_t *fp,              /* I - CUPS file */
          char        *buf,             /* I - Buffer */
          size_t      bytes)            /* I - Number bytes */
{
  ssize_t       total;                  /* Total bytes read */


  DEBUG_printf(("cups_read(fp=%p, buf=%p, bytes=" CUPS_LLFMT ")\n", fp, buf,
                CUPS_LLCAST bytes));

 /*
  * Loop until we read at least 0 bytes...
  */

  for (;;)
  {
#ifdef WIN32
    if (fp->mode == 's')
      total = (ssize_t)recv(fp->fd, buf, (unsigned)bytes, 0);
    else
      total = (ssize_t)read(fp->fd, buf, (unsigned)bytes);
#else
    if (fp->mode == 's')
      total = recv(fp->fd, buf, bytes, 0);
    else
      total = read(fp->fd, buf, bytes);
#endif /* WIN32 */

    DEBUG_printf(("cups_read: total=" CUPS_LLFMT "\n", CUPS_LLCAST total));

    if (total >= 0)
      break;

   /*
    * Reads can be interrupted by signals and unavailable resources...
    */

    if (errno == EAGAIN || errno == EINTR)
      continue;
    else
      return (-1);
  }

 /*
  * Return the total number of bytes read...
  */

  return (total);
}


/*
 * 'cups_write()' - Write to a file descriptor.
 */

static ssize_t                          /* O - Number of bytes written or -1 */
cups_write(cups_file_t *fp,             /* I - CUPS file */
           const char  *buf,            /* I - Buffer */
           size_t      bytes)           /* I - Number bytes */
{
  size_t        total;                  /* Total bytes written */
  ssize_t       count;                  /* Count this time */


  DEBUG_printf(("cups_write(fp=%p, buf=%p, bytes=" CUPS_LLFMT ")\n", fp, buf,
                CUPS_LLCAST bytes));

 /*
  * Loop until all bytes are written...
  */

  total = 0;
  while (bytes > 0)
  {
#ifdef WIN32
    if (fp->mode == 's')
      count = (ssize_t)send(fp->fd, buf, (unsigned)bytes, 0);
    else
      count = (ssize_t)write(fp->fd, buf, (unsigned)bytes);
#else
    if (fp->mode == 's')
      count = send(fp->fd, buf, bytes, 0);
    else
      count = write(fp->fd, buf, bytes);
#endif /* WIN32 */

    DEBUG_printf(("cups_write: count=" CUPS_LLFMT "\n", CUPS_LLCAST count));

    if (count < 0)
    {
     /*
      * Writes can be interrupted by signals and unavailable resources...
      */

      if (errno == EAGAIN || errno == EINTR)
        continue;
      else
        return (-1);
    }

   /*
    * Update the counts for the last write call...
    */

    bytes -= count;
    total += count;
    buf   += count;
  }

 /*
  * Return the total number of bytes written...
  */

  return ((ssize_t)total);
}


/*
 * End of "$Id: file.c 6962 2007-09-17 20:35:47Z mike $".
 */