perf tools: Add cat as fallback pager

This patch adds a fallback to cat for the pager. This is useful
on environments, such as Android, where less does not exist.
It is better to default to cat than to abort.

Signed-off-by: Michael Lentine <mlentine@google.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1400579330-5043-2-git-send-email-eranian@google.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

tools/perf/util/pager.c

@@ -57,13 +57,13 @@ void setup_pager(void)
 	}
 	if (!pager)
 		pager = getenv("PAGER");
-	if (!pager) {
-		if (!access("/usr/bin/pager", X_OK))
-			pager = "/usr/bin/pager";
-	}
+	if (!(pager || access("/usr/bin/pager", X_OK)))
+		pager = "/usr/bin/pager";
+	if (!(pager || access("/usr/bin/less", X_OK)))
+		pager = "/usr/bin/less";
 	if (!pager)
-		pager = "less";
-	else if (!*pager || !strcmp(pager, "cat"))
+		pager = "cat";
+	if (!*pager || !strcmp(pager, "cat"))
 		return;
 
 	spawned_pager = 1; /* means we are emitting to terminal */