From 4ff54f536e56f39a4fe934bc662e21b65ad38a7e Mon Sep 17 00:00:00 2001
From: Jean Jordaan <jean.jordaan@gmail.com>
Date: Fri, 18 Mar 2016 14:14:49 +0700
Subject: [PATCH 1/2] Allow to run as non-root; tidying

Start to allow running as non-root.
If not root, check only your own processes. However the `-r` check
succeeds when it should fail.

Fix abbreviations (KB, GB, ...).
Fix commenting, typos.
---
 memstat.sh | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/memstat.sh b/memstat.sh
index 953f693..761b045 100644
--- a/memstat.sh
+++ b/memstat.sh
@@ -6,27 +6,25 @@
 # this shell script tries best to find more accurate results. Script use 2 files ie /proc//status (to get name of process)
 # and /proc//smaps for memory statistic of process. Then script will convert all data into Kb, Mb, Gb. 
 # Also make sure you install bc command.
-
-
-Source : http://www.linoxide.com/linux-shell-script/linux-memory-usage-program/
-Parent : http://www.linoxide.com/guide/scripts-pdf.html
-
-# Make sure only root can run our script
+# 
+# Source : http://www.linoxide.com/linux-shell-script/linux-memory-usage-program/
+# Parent : http://www.linoxide.com/guide/scripts-pdf.html
+# 
 
 if [ "$(id -u)" != "0" ]; then
-   echo "This script must be run as root" 1>&2
-   exit 1
+   echo "Reporting memory usage only for the current user. Run as root to get usage for all processes." 1>&2
 fi
 
+
 ### Functions
 #This function will count memory statistic for passed PID
 get_process_mem ()
 {
 PID=$1
-#we need to check if 2 files exist
-if [ -f /proc/$PID/status ];
+#we need to check if 2 files exist (and are readable)
+if [ -r /proc/$PID/status ];
 then
-	if [ -f /proc/$PID/smaps ]; 
+	if [ -r /proc/$PID/smaps ]; 
 	then
 		#here we count memory usage, Pss, Private and Shared = Pss-Private
 		Pss=`cat /proc/$PID/smaps | grep -e "^Pss:" | awk '{print $2}'| paste -sd+ | bc `
@@ -48,7 +46,7 @@ then
 fi
 }
 
-#this function make conversion from bytes to Kb or Mb or Gb
+#this function make conversion from bytes to KB or MB or GB
 convert()
 {
 value=$1
@@ -66,12 +64,12 @@ do
 	let power=$power+1
 done
 
-#this part get b,kb,mb or gb according to number of divisions 
+#this part get B,KB,MB or GB according to number of divisions 
 case $power in
-	0) reg=b;;
-	1) reg=kb;;
-	2) reg=mb;;
-	3) reg=gb;;
+	0) reg=B;;
+	1) reg=KB;;
+	2) reg=MB;;
+	3) reg=GB;;
 esac
 
 echo -n "${value} ${reg} "
@@ -83,7 +81,9 @@ echo -n "${value} ${reg} "
 [[ -f /tmp/res3 ]] && rm -f /tmp/res3
 
 
-#if argument passed script will show statistic only for that pid, of not � we list all processes in /proc/ #and get statistic for all of them, all result we store in file /tmp/res
+# If argument passed, script will show statistics only for that PID, if not,
+# we list all processes in /proc/ and get statistics for all of them. 
+# All result we store in file /tmp/res
 if [ $# -eq 0 ]
 then
 	pids=`ls /proc | grep -e [0-9] | grep -v [A-Za-z] `
@@ -100,7 +100,7 @@ fi
 cat /tmp/res | sort -gr -k 5 > /tmp/res2
 
 #this part will get uniq names from process list, and we will add all lines with same process list 
-#we will count nomber of processes with same name, so if more that 1 process where will be
+#we will count number of processes with same name, so if more that 1 process where will be
 # process(2) in output
 for Name in `cat /tmp/res2 | awk '{print $6}' | sort  | uniq`
 do

From 60909d60df39a88e956efab355ea1ec3b64fe5d5 Mon Sep 17 00:00:00 2001
From: Jean Jordaan <jean.jordaan@gmail.com>
Date: Sun, 20 Mar 2016 22:40:22 +0700
Subject: [PATCH 2/2] Fix test to read proc info as non-root

See http://unix.stackexchange.com/a/270610/7944
---
 memstat.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/memstat.sh b/memstat.sh
index 761b045..9f9b087 100644
--- a/memstat.sh
+++ b/memstat.sh
@@ -22,9 +22,9 @@ get_process_mem ()
 {
 PID=$1
 #we need to check if 2 files exist (and are readable)
-if [ -r /proc/$PID/status ];
+if test -r /proc/$PID/status && head -n 1 /proc/$PID/status 2>/dev/null 1>/dev/null;
 then
-	if [ -r /proc/$PID/smaps ]; 
+	if test -r /proc/$PID/smaps && head -n 1 /proc/$PID/smaps 2>/dev/null 1>/dev/null; 
 	then
 		#here we count memory usage, Pss, Private and Shared = Pss-Private
 		Pss=`cat /proc/$PID/smaps | grep -e "^Pss:" | awk '{print $2}'| paste -sd+ | bc `