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From: Peter_Gutmann@kcbbs.gen.nz (Peter Gutmann)
Newsgroups: comp.compression
Subject: A few fixes for pgencode/pgdecode
Message-ID: <1991Mar29.102051.1743@kcbbs>
Date: 29 Mar 91 10:20:51 GMT
Lines: 52
Organisation: Kappa Crucis Unix BBS, Auckland, New Zealand

Oh dear!  It appears that a line of pgdecode was truncated at 80 columns   
(sorry folks!).  Here's the full version:  It's towards the end of the  
pgdecode source:  
  
    /* Nitpick to make sure there's an end line */  
    if( fgets( buffer, sizeof( buffer ), inFilePtr ) == NULL || \  
        strcmp( buffer, "end\n" ) )  
                  
Thanks to Michael Lawler for pointing this out.  
  
Also, after I'd posted the code I realised I was being a bit over-paranoid   
with the code in encodeFile()/decodeFile().  In particular replacing the two  
while loops:  
  
        while( bitCount < LONG_CODE_BITS )  
            {  
            bitBuffer |= getc( inFilePtr ) << bitCount;  
            bitCount += CHAR_BIT;  
            }  
  
and:  
  
        while( bitCount >= CHAR_BIT )  
            {  
            putc( bitBuffer & 0xFF, outFilePtr );  
            bitBuffer >>= CHAR_BIT;  
            bitCount -= CHAR_BIT;  
            }  
  
with simple if statements:  
  
        if( bitCount < LONG_CODE_BITS )  
  
and:  
  
        if( bitCount >= CHAR_BIT )  
  
should give a slight program speedup.  
  
Another thing which I think I should mention is that the encoded files may   
not pass unscathed through some networks:  I think some of the chars produced 
have no EBCDIC equivalent for example (but I'll let the experts comment on  
that one).  
  
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 Peter_Gutmann@kcbbs.gen.nz || peter@nacjack.gen.nz || pgut1@cs.aukuni.ac.nz  
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