This is a *NON official* patch to GNU tar 1.11.1 to support gzip. With
this patch, tar -cz invokes gzip, tar -cZ invokes compress. You can
use tar -xz to extract both compressed and gzip'ed tar files.
For example you can transfer files from one machine to another
in a compressed form using:

  tar cfz - files | rsh machine 'tar xvpfz -'

tar and gzip are available on all GNU archive sites, such as
prep.ai.mit.edu:/pub/gnu and its mirrors.

Jean-loup Gailly
jloup@chorus.fr

diff -c bak/buffer.c ./buffer.c
*** bak/buffer.c	Mon Sep 14 22:56:39 1992
--- ./buffer.c	Mon Dec 28 19:07:52 1992
***************
*** 452,459 ****
  		}
  	}
  		/* So we should exec compress (-d) */
! 	if(ar_reading)
  		execlp("compress", "compress", "-d", (char *)0);
  	else
  		execlp("compress", "compress", (char *)0);
  	msg_perror("can't exec compress");
--- 452,463 ----
  		}
  	}
  		/* So we should exec compress (-d) */
! 	if(ar_reading) {
! 		execlp("gzip", "gzip", "-d", (char *)0);
! 		/* Try uncompress if gunzip fails */
  		execlp("compress", "compress", "-d", (char *)0);
+ 	} else if (f_zip)
+ 		execlp("gzip", "gzip", "-8", (char *)0);
  	else
  		execlp("compress", "compress", (char *)0);
  	msg_perror("can't exec compress");
diff -c bak/tar.c ./tar.c
*** bak/tar.c	Mon Sep 14 23:31:38 1992
--- ./tar.c	Mon Dec 28 19:14:29 1992
***************
*** 158,163 ****
--- 158,164 ----
  	{"ignore-zeros",	0,	&f_ignorez,		1},
  	{"keep-old-files",	0,	0,			'k'},
  	{"uncompress",		0,	&f_compress,		1},
+         {"unzip",		0,	0,			'z'},
  	{"same-permissions",	0,	&f_use_protection,	1},
  	{"preserve-permissions",0,	&f_use_protection,	1},
  	{"modification-time",	0,	&f_modified,		1},
***************
*** 183,188 ****
--- 184,190 ----
  	{"old-archive",		0,	0,			'o'},
  	{"portability",		0,	0,			'o'},
  	{"compress",		0,	&f_compress,		1},
+         {"zip",			0,	0,			'z'},
  	{"compress-block",	0,	&f_compress,		2},
  	{"sparse",		0,	&f_sparse_files,	1},
  	{"tape-length",		1,	0,			'L'},
***************
*** 609,615 ****
  			add_exclude_file(optarg);
  			break;
  
! 		case 'z':		/* Easy to type */
  		case 'Z':		/* Like the filename extension .Z */
  			f_compress++;
  			break;
--- 611,621 ----
  			add_exclude_file(optarg);
  			break;
  
! 		case 'z':		/* Like the filename extension .z */
! 			f_zip++;
! 			f_compress++;
! 			break;
! 
  		case 'Z':		/* Like the filename extension .Z */
  			f_compress++;
  			break;
***************
*** 716,722 ****
  -W, --verify		attempt to verify the archive after writing it\n\
  --exclude FILE		exclude file FILE\n\
  -X, --exclude-from FILE	exclude files listed in FILE\n\
! -z, -Z, --compress,\n\
      --uncompress      	filter the archive through compress\n\
  -[0-7][lmh]		specify drive and density\n\
  ", stdout);
--- 722,729 ----
  -W, --verify		attempt to verify the archive after writing it\n\
  --exclude FILE		exclude file FILE\n\
  -X, --exclude-from FILE	exclude files listed in FILE\n\
! -z, --zip, --unzip	filter the archive through gzip\n\
! -Z, --compress,\n\
      --uncompress      	filter the archive through compress\n\
  -[0-7][lmh]		specify drive and density\n\
  ", stdout);
diff -c bak/tar.h ./tar.h
*** bak/tar.h	Tue Sep  8 21:45:34 1992
--- ./tar.h	Mon Dec 28 19:06:40 1992
***************
*** 224,231 ****
  TAR_EXTERN int  f_verify;		/* -W */
  			/* CMD_EXTRACT     -x */
  TAR_EXTERN int  f_exclude;		/* -X */
! TAR_EXTERN int 	f_compress;		/* -z */
! 					/* -Z */
  TAR_EXTERN int	f_do_chown;		/* --do-chown */
  TAR_EXTERN int  f_totals;		/* --totals */
  TAR_EXTERN int	f_remove_files;		/* --remove-files */
--- 224,231 ----
  TAR_EXTERN int  f_verify;		/* -W */
  			/* CMD_EXTRACT     -x */
  TAR_EXTERN int  f_exclude;		/* -X */
! TAR_EXTERN int 	f_zip;			/* -z */
! TAR_EXTERN int 	f_compress;		/* -Z */
  TAR_EXTERN int	f_do_chown;		/* --do-chown */
  TAR_EXTERN int  f_totals;		/* --totals */
  TAR_EXTERN int	f_remove_files;		/* --remove-files */