From 2b5903dea28b6f8181e69429d45b80433dc72522 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Mon, 5 Apr 2010 23:14:16 -0700
Subject: mincore: add '-s' summary option

This displays the percentage of the file mmap'ed.
---
 mincore.c         | 30 +++++++++++++++++++++++-------
 pcu-mincore.1.txt |  9 ++++++++-
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/mincore.c b/mincore.c
index 4bdbd0c..cafb63d 100644
--- a/mincore.c
+++ b/mincore.c
@@ -1,8 +1,10 @@
 #include "compat-util.h"
+static int summary;
 
 static int usage(const char * argv0)
 {
-	fprintf(stderr, "Usage: %s [-o OFFSET] [-l LENGTH] FILE...\n", argv0);
+	fprintf(stderr,
+	        "Usage: %s [-o OFFSET] [-l LENGTH] [-s] FILE...\n", argv0);
 	return 1;
 }
 
@@ -57,10 +59,19 @@ static void mincore_stats(const char *path, off_t offset, off_t len)
 		goto err_munmap;
 	}
 
-	for (i = 0; i < vec_len; ++i)
-		printf(fmt, path,
-		       (unsigned long)((page_size() * i) + map_offset),
-		       vec[i] & 1);
+	if (summary) {
+		size_t n = 0;
+
+		for (i = 0; i < vec_len; ++i)
+			if (vec[i] & 1)
+				++n;
+		printf("%s: %F\n", path, (double)n / (double)vec_len);
+	} else {
+		for (i = 0; i < vec_len; ++i)
+			printf(fmt, path,
+			       (unsigned long)((page_size() * i) + map_offset),
+			       vec[i] & 1);
+	}
 err_munmap:
 	munmap(map, map_len);
 err_free:
@@ -76,12 +87,13 @@ int main(int argc, char * const argv[])
 	int argi = 1;
 	int opt;
 
-	while ((opt = getopt(argc, argv, "o:l:h")) != -1) {
+	while ((opt = getopt(argc, argv, "o:l:hs")) != -1) {
 		char *err;
 
-		argi += 2;
+		++argi;
 		switch(opt) {
 		case 'o':
+			++argi;
 			offset = cstr_to_off_t(optarg, &err, 10);
 			if (*err || offset < 0) {
 				fprintf(stderr, "offset must be >= 0\n");
@@ -89,12 +101,16 @@ int main(int argc, char * const argv[])
 			}
 			break;
 		case 'l':
+			++argi;
 			len = cstr_to_off_t(optarg, &err, 10);
 			if (*err || len < 0) {
 				fprintf(stderr, "length must be >= 0\n");
 				return 1;
 			}
 			break;
+		case 's':
+			summary = 1;
+			break;
 		default:
 			return usage(argv[0]);
 		}
diff --git a/pcu-mincore.1.txt b/pcu-mincore.1.txt
index a3a8300..e0d9075 100644
--- a/pcu-mincore.1.txt
+++ b/pcu-mincore.1.txt
@@ -6,7 +6,7 @@
 pcu-mincore - shows cache status for given files
 
 # SYNOPSIS
-pcu-mincore [-o OFFSET] [-l LENGTH] FILE...
+pcu-mincore [-o OFFSET] [-l LENGTH] [-s] FILE...
 
 # DESCRIPTION
 A command-line interface to the mincore(2) syscall to inspect
@@ -24,7 +24,14 @@ resident memory.
     This length is rounded up next page offset.
     The default is to scan the entire file.
 
+-s
+:   Display the summary output as a floating point number between
+    0.0 and 1.0 representing the percentage of the file in core.
+
 # OUTPUT
+The following output is displayed unless "-s" summary format
+is chosen.
+
 One line for every page scanned in the following format:
 
    \<filename\>: \<offset\> \<incore\>
-- 
cgit v1.2.3-24-ge0c7