[PATCH 08/10] perf, tools: Query terminal width and use in perf list

[Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>]

From: Andi Kleen <ak@linux.intel.com>

Automatically adapt the now wider and word wrapped perf list
output to wider terminals. This requires querying the terminal
before the auto pager takes over, and exporting this
information from the pager subsystem.

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 tools/perf/util/cache.h |    1 +
 tools/perf/util/pager.c |   15 +++++++++++++++
 tools/perf/util/pmu.c   |    3 ++-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index fbcca21..edf0398 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -33,6 +33,7 @@ extern void setup_pager(void);
 extern const char *pager_program;
 extern int pager_in_use(void);
 extern int pager_use_color;
+int pager_get_columns(void);
 
 char *alias_lookup(const char *alias);
 int split_cmdline(char *cmdline, const char ***argv);
diff --git a/tools/perf/util/pager.c b/tools/perf/util/pager.c
index 31ee02d..9761202 100644
--- a/tools/perf/util/pager.c
+++ b/tools/perf/util/pager.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "run-command.h"
 #include "sigchain.h"
+#include <sys/ioctl.h>
 
 /*
  * This is split up from the rest of git so that we can do
@@ -8,6 +9,7 @@
  */
 
 static int spawned_pager;
+static int pager_columns;
 
 static void pager_preexec(void)
 {
@@ -47,9 +49,12 @@ static void wait_for_pager_signal(int signo)
 void setup_pager(void)
 {
 	const char *pager = getenv("PERF_PAGER");
+	struct winsize sz;
 
 	if (!isatty(1))
 		return;
+	if (ioctl(1, TIOCGWINSZ, &sz) == 0)
+		pager_columns = sz.ws_col;
 	if (!pager) {
 		if (!pager_program)
 			perf_config(perf_default_config, NULL);
@@ -98,3 +103,13 @@ int pager_in_use(void)
 	env = getenv("PERF_PAGER_IN_USE");
 	return env ? perf_config_bool("PERF_PAGER_IN_USE", env) : 0;
 }
+
+int pager_get_columns(void)
+{
+	char *s;
+
+	s = getenv("COLUMNS");
+	if (s)
+		return atoi(s);
+	return (pager_columns ? pager_columns : 80) - 2;
+}
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 98c0a40..eca379c 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -13,6 +13,7 @@
 #include "pmu-events/pmu-events.h"
 #include "cpumap.h"
 #include "header.h"
+#include "cache.h"
 
 struct perf_pmu_format {
 	char *name;
@@ -980,7 +981,7 @@ void print_pmu_events(const char *event_glob, bool name_only)
 	int len, j;
 	struct pair *aliases;
 	int numdesc = 0;
-	int columns = 78;
+	int columns = pager_get_columns();
 
 	pmu = NULL;
 	len = 0;
-- 
1.7.9.5