[PATCH] progress: use \r as EOL only if isatty(stderr) is true

[Steffen Daode Nurpmeso <sdaoden@googlemail.com>]

So far progress always uses \r to produce one-line output on stderr.
This only produces useful and easy parsable output if stderr is opened
on a file which does interpret CR as a real carriage return operation.
This patch changes EOL to the plain newline \n control if isatty() is
false instead.

Signed-off-by: Steffen Daode Nurpmeso <sdaoden@gmail.com>
---
 progress.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/progress.c b/progress.c
index 3971f49..c548de4 100644
--- a/progress.c
+++ b/progress.c
@@ -27,6 +27,7 @@ struct throughput {
 
 struct progress {
 	const char *title;
+	const char *eol;
 	int last_value;
 	unsigned total;
 	unsigned last_percent;
@@ -90,7 +91,7 @@ static int display(struct progress *progress, unsigned n, const char *done)
 
 	progress->last_value = n;
 	tp = (progress->throughput) ? progress->throughput->display : "";
-	eol = done ? done : "   \r";
+	eol = done ? done : progress->eol;
 	if (progress->total) {
 		unsigned percent = n * 100 / progress->total;
 		if (percent != progress->last_percent || progress_update) {
@@ -219,6 +220,7 @@ struct progress *start_progress_delay(const char *title, unsigned total,
 		return NULL;
 	}
 	progress->title = title;
+	progress->eol = isatty(fileno(stderr)) ? "   \r" : "\n";
 	progress->total = total;
 	progress->last_value = -1;
 	progress->last_percent = -1;
-- 
1.7.6.rc0