fixes #34

for now this just adds the `-c` option and completely ignores it

src/pixz.c

@@ -45,6 +45,7 @@ static void usage(const char *msg) {
 "  -p NUM             Use a maximum of NUM CPU-intensive threads\n"
 "  -t                 Don't assume input is in tar format\n"
 "  -k                 Keep original input (do not remove it)\n"
+"  -c                 ignored"
 "  -h                 Print this help\n"
 "\n"
 "pixz %s\n"
@@ -67,8 +68,9 @@ int main(int argc, char **argv) {
 	char *optend;
 	long optint;
     double optdbl;
-    while ((ch = getopt(argc, argv, "dxli:o:tkvhp:0123456789f:q:e")) != -1) {
+    while ((ch = getopt(argc, argv, "dcxli:o:tkvhp:0123456789f:q:e")) != -1) {
         switch (ch) {
+            case 'c': break;
             case 'd': op = OP_READ; break;
             case 'x': op = OP_EXTRACT; break;
             case 'l': op = OP_LIST; break;

test/Makefile.am

@@ -1,5 +1,6 @@
 TESTS = \
-	single-file-round-trip.sh
+	single-file-round-trip.sh \
+	xz-compatibility-c-option.sh
 
 EXTRA_DIST = $(TESTS)
 

test/xz-compatibility-c-option.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+PIXZ=../src/pixz
+
+[[ "foo" = $(echo foo | xz    | xz    -dc) ]] || exit 1
+[[ "bar" = $(echo bar | $PIXZ | $PIXZ -dc) ]] || exit 1