From bd88864d8ee15a65d5ecdb3818afa4d5193d2455 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Skytt=C3=A4?= <ville.skytta@iki.fi>
Date: Thu, 12 Apr 2018 08:39:20 +0300
Subject: [PATCH] usage: Output to stdout on exit code 0

---
 src/pattern.c | 6 +++---
 src/pattern.h | 4 +++-
 src/scrub.c   | 7 ++++---
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/pattern.c b/src/pattern.c
index 10430f9..6c0eedc 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -420,7 +420,7 @@ seq2str(const sequence_t *sp, char *buf, int len)
 }
 
 void
-seq_list(void)
+seq_list(FILE *fp)
 {
     const int len = seq_count();
     char buf[80];
@@ -428,10 +428,10 @@ seq_list(void)
 
     for (i = 0; i < len; i++) {
         seq2str(sequences[i], buf, sizeof(buf));
-        fprintf(stderr, "%s\n", buf);
+        fprintf(fp, "%s\n", buf);
     }
     seq2str(&custom_seq, buf, sizeof(buf));
-    fprintf(stderr, "%s\n", buf);
+    fprintf(fp, "%s\n", buf);
 }
 
 /*
diff --git a/src/pattern.h b/src/pattern.h
index bcf5374..e1d0144 100644
--- a/src/pattern.h
+++ b/src/pattern.h
@@ -1,3 +1,5 @@
+#include <stdio.h>
+
 #define MAXPATBYTES 16
 #define MAXSEQPATTERNS 35
 typedef enum {
@@ -19,7 +21,7 @@ typedef struct {
 } sequence_t;
 
 const sequence_t *seq_lookup(char *name);
-void              seq_list(void);
+void              seq_list(FILE *fp);
 char             *pat2str(pattern_t p);
 void              memset_pat(void *s, pattern_t p, size_t n);
 
diff --git a/src/scrub.c b/src/scrub.c
index fceb639..6671ed5 100644
--- a/src/scrub.c
+++ b/src/scrub.c
@@ -112,7 +112,8 @@ char *prog;
 static void 
 usage(int rc)
 {
-    fprintf(stderr,
+    FILE *fp = rc ? stderr : stdout;
+    fprintf(fp,
 "Usage: %s [OPTIONS] file [file...]\n"
 "  -v, --version           display scrub version and exit\n"
 "  -p, --pattern pat       select scrub pattern sequence\n"
@@ -130,8 +131,8 @@ usage(int rc)
 "  -h, --help              display this help message\n"
     , prog);
 
-    fprintf(stderr, "Available patterns are:\n");
-    seq_list ();
+    fprintf(fp, "Available patterns are:\n");
+    seq_list (fp);
     exit(rc);
 }