[PATCH v21 07/19] perf, tools: Query terminal width and use in perf list

[Sukadev Bhattiprolu]

From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

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.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
---

Changelog[v20]
	- Minor reorg since helpers like setup_pager() are now in
	  tools/lib/subcmd/pager.c
---
 tools/lib/subcmd/pager.c | 16 ++++++++++++++++
 tools/lib/subcmd/pager.h |  1 +
 tools/perf/util/pmu.c    |  3 ++-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/lib/subcmd/pager.c b/tools/lib/subcmd/pager.c
index d50f3b58..6518bea 100644
--- a/tools/lib/subcmd/pager.c
+++ b/tools/lib/subcmd/pager.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <signal.h>
+#include <sys/ioctl.h>
 #include "pager.h"
 #include "run-command.h"
 #include "sigchain.h"
@@ -14,6 +15,7 @@
  */
 
 static int spawned_pager;
+static int pager_columns;
 
 void pager_init(const char *pager_env)
 {
@@ -58,9 +60,12 @@ static void wait_for_pager_signal(int signo)
 void setup_pager(void)
 {
 	const char *pager = getenv(subcmd_config.pager_env);
+	struct winsize sz;
 
 	if (!isatty(1))
 		return;
+	if (ioctl(1, TIOCGWINSZ, &sz) == 0)
+		pager_columns = sz.ws_col;
 	if (!pager)
 		pager = getenv("PAGER");
 	if (!(pager || access("/usr/bin/pager", X_OK)))
@@ -98,3 +103,14 @@ int pager_in_use(void)
 {
 	return spawned_pager;
 }
+
+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/lib/subcmd/pager.h b/tools/lib/subcmd/pager.h
index 8b83714..623f554 100644
--- a/tools/lib/subcmd/pager.h
+++ b/tools/lib/subcmd/pager.h
@@ -5,5 +5,6 @@ extern void pager_init(const char *pager_env);
 
 extern void setup_pager(void);
 extern int pager_in_use(void);
+extern int pager_get_columns(void);
 
 #endif /* __SUBCMD_PAGER_H */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index af1a612..ef9de3e 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -14,6 +14,7 @@
 #include "cpumap.h"
 #include "header.h"
 #include "pmu-events/pmu-events.h"
+#include "cache.h"
 
 struct perf_pmu_format {
 	char *name;
@@ -1093,7 +1094,7 @@ 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;
-- 
1.8.3.1