Actually implement gzip's -c option. minigzip now also doubles

as zcat properly.

PR:		13043
Submitted by:	Toshihiko ARAI <toshi@jp.freebsd.org>
		Jonathan Towne <jontow@twcny.rr.com>

Approved by:	peter, sheldonh (mentor)
MFC After:	2 weeks

2 files changed, 43 insertions, 7 deletions

diff --git a/lib/libz/minigzip.c b/lib/libz/minigzip.c
index 3617dfc..076aa2c 100644
--- a/lib/libz/minigzip.c
+++ b/lib/libz/minigzip.c
@@ -271,7 +271,8 @@ void file_uncompress(file)
 
 
 /* ===========================================================================
- * Usage:  minigzip [-d] [-f] [-h] [-1 to -9] [files...]
+ * Usage:  minigzip [-c ] [-d] [-f] [-h] [-1 to -9] [files...]
+ *   -c : write to standard output
  *   -d : decompress
  *   -f : compress with Z_FILTERED
  *   -h : compress with Z_HUFFMAN_ONLY
@@ -282,6 +283,7 @@ int main(argc, argv)
     int argc;
     char *argv[];
 {
+    int copyout = 0;
     int uncompr = 0;
     gzFile file;
     char *bname, outmode[20];
@@ -296,12 +298,14 @@ int main(argc, argv)
       bname = argv[0];
     argc--, argv++;
 
-    if (!strcmp(bname, "gunzip") || !strcmp(bname, "zcat"))
+    if (!strcmp(bname, "gunzip"))
       uncompr = 1;
+    else if (!strcmp(bname, "zcat"))
+      copyout = uncompr = 1;
 
     while (argc > 0) {
       if (strcmp(*argv, "-c") == 0)
-	; /* Just for compatibility with gzip */
+	copyout = 1;
       else if (strcmp(*argv, "-d") == 0)
 	uncompr = 1;
       else if (strcmp(*argv, "-f") == 0)
@@ -328,11 +332,36 @@ int main(argc, argv)
             gz_compress(stdin, file);
         }
     } else {
+	if (copyout) {
+	    SET_BINARY_MODE(stdout);
+	}
         do {
             if (uncompr) {
-                file_uncompress(*argv);
+	    	if (copyout) {
+		    file = gzopen(*argv, "rb");
+		    if (file == NULL)
+			fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
+		    else
+			gz_uncompress(file, stdout);
+		} else {
+		    file_uncompress(*argv);
+		}
             } else {
-                file_compress(*argv, outmode);
+		if (copyout) {
+		    FILE * in = fopen(*argv, "rb");
+
+		    if (in == NULL) {
+			perror(*argv);
+		    } else {
+		        file = gzdopen(fileno(stdout), outmode);
+			if (file == NULL) error("can't gzdopen stdout");
+
+			gz_compress(in, file);
+		    }
+		
+		} else {
+		    file_compress(*argv, outmode);
+		}
             }
         } while (argv++, --argc);
     }
diff --git a/usr.bin/minigzip/minigzip.1 b/usr.bin/minigzip/minigzip.1
index 0bfe899..7759296 100644
--- a/usr.bin/minigzip/minigzip.1
+++ b/usr.bin/minigzip/minigzip.1
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 13, 1997
+.Dd October 3, 2002
 .Dt MINIGZIP 1
 .Os
 .Sh NAME
@@ -32,7 +32,7 @@
 .Nd minimal implementation of the 'gzip' compression tool
 .Sh SYNOPSIS
 .Nm
-.Op Fl d
+.Op Fl cd
 .Op Ar
 .Sh DESCRIPTION
 The
@@ -64,6 +64,13 @@ arguments are supplied,
 .Nm
 reads from standard input and writes the results of the operation
 to standard output.
+.Pp
+If the
+.Fl c
+option is specified, 
+.Nm
+writes the results to standard output and keep the original files
+unchanged.
 .Sh SEE ALSO
 .Xr gzip 1
 .Sh AUTHORS