From 5106b550d36f50572cea55690075f0f07cee2994 Mon Sep 17 00:00:00 2001
From: Alexis Ben Miloud--Josselin <abenmiloud+git@evolix.fr>
Date: Mon, 16 Jul 2018 16:56:25 +0200
Subject: [PATCH] Make the code warning-free

Using `shellcheck -s sh kvmstats.sh`.
---
 kvmstats.sh | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/kvmstats.sh b/kvmstats.sh
index 2daaa9d..d465b8c 100644
--- a/kvmstats.sh
+++ b/kvmstats.sh
@@ -12,7 +12,7 @@ usage () {
 }
 
 POW=$(echo 1024 ^ 3 | bc)
-while echo $1 | grep -q '^-[[:alnum:]]'
+while [ $# -ne 0 ] && echo "$1" | grep -q '^-[[:alnum:]]'
 do
     case $1 in
     '-u')
@@ -37,7 +37,7 @@ do
 done
 
 # since libvirt seems to store memoy in KiB, POW must be lowered by 1
-POW=$(expr $POW / 1024)
+POW=$((POW / 1024))
 
 for DEP in hxselect lvs tempfile
 do
@@ -51,34 +51,35 @@ done
 TMPFILE=$(tempfile)
 LVSOUT=$(tempfile)
 
-lvs --units b --nosuffix >$LVSOUT
+lvs --units b --nosuffix >"$LVSOUT"
 
 for VM in $(virsh list --all --name)
 do
-    VCPU=$(hxselect -c 'domain vcpu' </etc/libvirt/qemu/$VM.xml)
-    RAM=$(expr $(hxselect -c 'domain memory' </etc/libvirt/qemu/$VM.xml) / $POW)
-    for DEV in $(hxselect -s'\n' 'domain devices disk[device=disk] source' </etc/libvirt/qemu/$VM.xml | cut -d\" -f2)
+    VCPU=$(hxselect -c 'domain vcpu' </etc/libvirt/qemu/"$VM.xml")
+    RAM_KIB=$(hxselect -c 'domain memory' </etc/libvirt/qemu/"$VM.xml")
+    RAM=$((RAM_KIB / POW))
+    for DEV in $(hxselect -s'\n' 'domain devices disk[device=disk] source' </etc/libvirt/qemu/"$VM.xml" | cut -d\" -f2)
     do
         case $DEV in
         /dev/drbd/*)
-            DISK=$(cat $LVSOUT | awk "/$VM/ { ans += \$NF } END { print ans / 1024 ^ 3 }")
+            DISK=$(awk "/$VM/ { ans += \$NF } END { print ans / 1024 ^ 3 }" <"$LVSOUT")
             break # avoid to compute DISK for each disk
             ;;
         *.qcow2)
-            DISK=$(du -sBG $DEV | awk '{ print substr($1, 0, length($1) - 1) }')
+            DISK=$(du -sBG "$DEV" | awk '{ print substr($1, 0, length($1) - 1) }')
             ;;
         *)
             DISK=0
             esac
     done
-    RUNNING=$(virsh domstate $VM | grep -q '^running$' && echo X)
-    echo $VM $VCPU $RAM $DISK $RUNNING
-done >$TMPFILE
+    RUNNING=$(virsh domstate "$VM" | grep -q '^running$' && echo X)
+    echo "$VM $VCPU $RAM $DISK $RUNNING"
+done >"$TMPFILE"
 
 (
     echo vm vcpu ram disk running
-    cat $TMPFILE
-    awk '{ vcpu += $2; ram += $3; disk += $4; running += length($5) } END { print "TOTAL", vcpu, ram, disk, running }' <$TMPFILE
+    cat "$TMPFILE"
+    awk '{ vcpu += $2; ram += $3; disk += $4; running += length($5) } END { print "TOTAL", vcpu, ram, disk, running }' <"$TMPFILE"
 ) | column -t
 
-rm $TMPFILE $LVSOUT
+rm "$TMPFILE" "$LVSOUT"