Xref: utzoo comp.compression:544 comp.lang.perl:5267
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From: bill@camco.Celestial.COM (Bill Campbell)
Newsgroups: comp.compression,comp.lang.perl
Subject: Problems running compress from perl on MS-DOS
Summary: Runs out of memory, output garbled
Keywords: compress, perl, MS-DOS
Message-ID: <991@camco.Celestial.COM>
Date: 9 May 91 20:42:03 GMT
Followup-To: comp.compression
Organization: Celestial Software, Mercer Island, WA
Lines: 47

I am trying to build an archive of compressed files on an MS-DOS
system using a perl script.  The guts are:
	open(INPUT, "filelist");	# opens input file list
	open(ARCHIVE, "archive");
	binmode(ARCHIVE);
	$buf_size = 512;
	while(<INPUT>) {
		chop;
		system("compress < $_ > tmpfile.Z");
		$comp_size = (stat('tmpfile.Z'))[7];
		&write_file_header();	# contains, names, sizes...
		open(WORKFILE, "tmpfile.Z");
		binmode(WORKFILE);
		$\ = '';	# don't insert anything after each write
		while(sysread(WORKFILE, $buffer, $buf_size) > 0) {
			print ARCHIVE $buffer;
			undef($buffer);	# strange stuff remaining on short
							# read if I don't do this.
		}
		close(WORKFILE);
	}
	close(INPUT);....

This works fine on Xenix/Unix systems, but the MS-DOS version has
one of two problems:
	1.	It frequently says that it is out of memory compressing
		from stdin.  I have recompiled compress for 12-bit
		compression and it does this less frequently, but it
		still does it.
	2.	The compressed file is longer than it should be.  It
		appears that it might be created as a text file rather
		than binary when the standard output is redirected to the
		file.

I'm using compress,v 4.3d compiled with Xenix cc -dos in large model.

I don't know much about MS-DOS (by choice), and don't understand
why this should fail in this manner.  Compressing in-place works
fine under MS-DOS.

Does anybody know what I'm doing wrong?

Thanks
-- 
INTERNET:  bill@Celestial.COM   Bill Campbell; Celestial Software
UUCP:   ...!thebes!camco!bill   6641 East Mercer Way
             uunet!camco!bill   Mercer Island, WA 98040; (206) 947-5591