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/* unzip.c -- decompress files in gzip or pkzip format. 
 * Copyright (C) 1992-1993 Jean-loup Gailly 
 * This is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License, see the file COPYING. 
 * 
 * The code in this file is derived from the file funzip.c written 
 * and put in the public domain by Mark Adler. 
 */ 
 
#include "gzip.h" 
 
/* =========================================================================== 
 * Unzip in to out.  This routine works on both gzip and pkzip files. 
 * 
 * IN assertions: the buffer inbuf contains already the beginning of 
 *   the compressed data, from offsets inptr to insize-1 included. 
 *   The magic header has already been checked. The output buffer is cleared. 
 */ 
 
int unzip( void ) 
{ 
    ulg orig_crc = 0;       /* original crc */ 
    ulg orig_len = 0;       /* original uncompressed length */ 
    int n;    uch buf[8];        /* extended local header */ 
 
    updcrc( NULL, 0 );           /* initialize crc */ 
 
    /* Decompress */ 
    inflate(); 
 
    for ( n = 0; n < 8; n ++) /* Get the crc and original length */ 
    { 
        buf[n] = ( uch )get_byte(); /* may cause an error if EOF */ 
    } 
 
    orig_crc = LG( buf ); 
    orig_len = LG( buf + 4 );    /* Validate decompression */ 
 
    if ( orig_crc != updcrc( outbuf, 0 )) 
    { 
        error( "invalid compressed data--crc error" ); 
    } 
 
    if ( orig_len != ( ulg )bytes_out ) 
    { 
        error( "invalid compressed data--length error" ); 
    } 
 
    return 0; 
}