added measure_latency.sh

README.md

@@ -64,6 +64,27 @@ actual entropy:  84.0964047444 bits
 
 * **chkrootkit.sh** - run chkrootkit then log & email results (chkrootkit is required)
 
+* *measure_latency.sh* - a quick and dirty latency measurement tool
+
+NOTE: This is just a quick tool to use so you don't have to bust out of the terminal, if you want historic views, use smokeping.
+
+```
+chad@macbookpro:~$ ./measure_latency.sh yahoo.com
+ERROR: You must supply a hostname/IP to measure & a packet count!
+  e.g. ./measure_latency.sh <hostname/ip> <count>
+chad@macbookpro:~$ ./measure_latency.sh 8.8.4.4 10
+latency to 8.8.4.4 with 10 packets is: 74.735 ms
+chad@macbookpro:~$ ./measure_latency.sh msn.com 10
+latency measurement failed: 100.0% packet loss
+
+-- or on linux --
+
+ubuntu@ubuntu-xenial:~$ ./measure_latency.sh 8.8.8.8 10
+latency to 8.8.8.8 with 10 packets is: 203.783 ms
+ubuntu@ubuntu-xenial:~$ ./measure_latency.sh msn.com 10
+latency measurement failed: 100% packet loss
+```
+
 * **randomize_mac.sh** - randomize mac addresses on macOS and Linux. This will help circumvent free wifi time limits in coffee shops and such. (This was actually an experiment until I begain using it more and more. I know about and have used machanger and spoofMAC, but I wanted to use something I wrote!)
 ```
 macbookpro:~ $ ifconfig en0 | grep ether

measure_latency.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+
+# measure_latency.sh - a dirty measure of latency via ping
+
+# NOTE: This was only written so I could test latency quickly if I needed
+#       to while in the terminal (which is where I spend all my time). If
+#       you really want to view latency over time, use smokeping
+
+usage() {
+    echo "  e.g. $0 <hostname/ip> <count>"
+}
+
+if [ $# -ne 2 ]; then
+    echo "ERROR: You must supply a hostname/IP to measure & a packet count!"
+    usage
+    exit 1
+fi
+
+server=$1
+count=$2
+success=0
+
+if [[ $OSTYPE =~ "darwin" ]]; then
+    # mac ping has different options that on linux
+    while read line
+    do
+        # check if we successfully ran
+        if [[ $line =~ "round-trip" ]]; then
+            latency=$(echo $line | awk -F "/" '/round-trip/ {print $7}')
+            echo "latency to $server with $count packets is: $latency"
+            success=1 && exit 0
+        fi
+
+        # check packet loss if we didn't run correctly
+        if [[ $line =~ "transmitted" ]] && [[ $success -ne 1 ]]; then
+            pct=$(echo $line | awk '/transmitted/ {print $(NF-2)}' | \
+                   awk -F. '{print $1}')
+
+            # check packet loss
+            if [ $pct -eq 100 ]; then
+                loss=$(echo $line |awk '/tted/ {print $(NF-2),$(NF-1),$NF}')
+                echo "latency measurement failed: $loss"
+            fi
+        fi
+    done < <(ping -q -c $count -i 0.2 -t 3 $server)
+
+elif [[ $OSTYPE =~ "linux" ]]; then
+    # http://homepage.smc.edu/morgan_david/cs70/assignments/ping-latency.htm
+    while read line
+    do
+        # check if we successfully ran
+        if [[ $line =~ "rtt" ]]; then
+            latency=$(echo $line | awk -F "/" '/rtt/ {print $5 " ms"}')
+            echo "latency to $server with $count packets is: $latency"
+            success=1 && exit 0
+        fi
+
+        # check packet loss if we didn't run correctly
+        if [[ $line =~ "transmitted" ]] && [[ $success -ne 1 ]]; then
+            pct=$(echo $line |awk '/transmitted/ {print $6}' | sed 's/%//g')
+
+            # check packet loss
+            if [ $pct -eq 100 ]; then
+                loss=$(echo $line |awk '/mitted/ {print $6" "$7" "$8}' | \
+                       sed 's/,//g')
+                echo "latency measurement failed: $loss"
+            fi
+        fi
+    done < <(ping -q -c $count -i 0.2 -w 3 $server)
+
+else
+    echo "ERROR: Unknown OS ($OSTYPE)"
+fi
+
+#EOF