[PATCH 2/6] Query terminal for word wrap length

[Andi K. <an...@fi...>]

From: Andi Kleen <ak...@li...>

If the output device of ophelp is a terminal query it for the line width,
instead of hardcoding 99.

Signed-off-by: Andi Kleen <ak...@li...>
---
 utils/ophelp.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/utils/ophelp.c b/utils/ophelp.c
index a87a640..1b3d215 100644
--- a/utils/ophelp.c
+++ b/utils/ophelp.c
@@ -14,6 +14,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
 
 #include "op_version.h"
 #include "op_events.h"
@@ -61,13 +63,21 @@ static void do_arch_specific_event_help(struct op_event * event)
 	}
 }
 
-#define LINE_LEN 99
+static int line_len = 99;
+
+static void set_linelen(void)
+{
+	struct winsize ws;
+
+	if (isatty(1) && ioctl(1, TIOCGWINSZ, &ws) >= 0)
+		line_len = ws.ws_col;
+}
 
 static void word_wrap(int indent, int *column, char *msg)
 {
 	while (*msg) {
 		int wlen = strcspn(msg, " ");
-		if (*column + wlen > LINE_LEN) {
+		if (*column + wlen > line_len) {
 			printf("\n%*s", indent, "");
 			*column = indent;
 		}
@@ -92,6 +102,8 @@ static void help_for_event(struct op_event * event)
 	size_t nr_counters;
 	char buf[32];
 
+	set_linelen();
+
 	do_arch_specific_event_help(event);
 	nr_counters = op_get_nr_counters(cpu_type);
 
-- 
1.7.4