perf tools: Query terminal width and use in perf list

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: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1473978296-20712-8-git-send-email-sukadev@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

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;
+}

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 */

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;
@@ -1092,7 +1093,7 @@ 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;