/*-------------------------------------------------------------------------*/
/**
   @file    compress_i.h
   @author  N. Devillard
   @date    Mar 2000
   @version $Revision: 1.4 $
   @brief   Interface to files compressed with @c compress.

   This module enables to read files compressed with the @c compress
   Unix command (if available on the local system). It does not try
   to understand the file format, but accesses the file through a 
   pipe to the @c compress command.
*/
/*--------------------------------------------------------------------------*/

/*
	$Id: compress_i.h,v 1.4 2001/10/17 10:29:01 ndevilla Exp $
	$Author: ndevilla $
	$Date: 2001/10/17 10:29:01 $
	$Revision: 1.4 $
*/

#ifndef _COMPRESS_I_H_
#define _COMPRESS_I_H_

/*---------------------------------------------------------------------------
   								Includes
 ---------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


/*---------------------------------------------------------------------------
						Function ANSI prototypes
 ---------------------------------------------------------------------------*/

/*-------------------------------------------------------------------------*/
/**
  @brief    Find out if a given file name corresponds to a compress'd file.
  @param    filename    Name of the file to check out.
  @return   1 if the file is compress'd, 0 if not, -1 if error.

  This function finds out if a given character string is the name of a
  valid compressed file (a file compressed with the 'compress'
  command). Be careful that the returned value is more than a
  true/false flag, it can also be -1 if an error occurred (e.g. the
  given file name does not correspond to any existing file).

  A compress'd file is recognized by the fact that the first two bytes
  in the files are respectively 0x1f and 0x9d (magic number, according
  to compress documentation).
 */
/*--------------------------------------------------------------------------*/
int is_compressed_file(char * filename);

/*-------------------------------------------------------------------------*/
/**
  @brief    Open a compress'd file in read-only mode as if uncompressed.
  @param    name    Name of the compressed file to open.
  @return   FILE pointer to the opened file.

  This function calls uncompress through a named pipe to get the
  uncompressed bytes. This means that the 'uncompress' command must be
  installed on the local system and available in the user's path.

  The received bytes are read-only and sequential. The returned FILE
  pointer corresponds to a non-seekable file because it is created by
  a popen() call.

  The returned FILE pointer must be closed using compress_close().
 */
/*--------------------------------------------------------------------------*/
FILE * compress_open(char * name);

/*-------------------------------------------------------------------------*/
/**
  @brief    Close out named pipe associated to compressed open file.
  @param    p FILE pointer to close.
  @return   void

  Calls pclose() on the given FILE pointer.
 */
/*--------------------------------------------------------------------------*/
void compress_close(FILE * p);

#endif