adds time range, help text, more time syntax flexibility

timed_ice_pause.sh

@@ -1,5 +1,29 @@
 #!/bin/bash
-
+# --------------------------------------------------------------------------- #
+# timed_ice_pause.sh
+#
+# use this script to regularly pause traffic on a WANlink by
+# dropping all packets for a specified amount of time
+#
+# -n     name of wanlink
+# -r     run for time period
+# -p     pause traffic for time period
+# -h     show help
+# -S     seconds
+# -M     minutes
+# -H     hours
+# -D     days
+#
+# Time period should be a valid argument to sleep(1):
+#  5s    5 seconds
+#  6m    6 minutes
+#  7h    7 hours
+#  8d    8 days
+#
+# Time ranges have to be valid input to shuf(1), just integers:
+#  1-10  => shuf -i 1-10 -n 1
+#
+# --------------------------------------------------------------------------- #
 # scripts
 cd /home/lanforge/scripts
 trap do_sigint INT
@@ -29,7 +53,7 @@ function start_cx() {
 
 function pause_wl() {
    [ -z "$1" ] && echo "No connection name, bye." && exit 1
-   [ -z "$2" ] && echo "No sleep seconds, bye." && exit 1
+   [ -z "$2" ] && echo "No sleep time, bye." && exit 1
    local name=$1
    local pause_time=$2
 
@@ -94,19 +118,42 @@ function pause_wl() {
    echo -n " go "
 }
 
+# provide either a number or a pair of numbers joined by a dash to
+# generate a random value in that range
+# select_range 1  returns 1
+# select_range 1-10 returns
+function select_range() {
+   [ -z "$1" ] && "echo select_range wants a numeric string, bye" && exit 1
+
+   if [[ $1 = *-* ]]; then
+      echo "$(shuf -i $1 -n1)$unit"
+   else
+      echo "$1"
+   fi
+}
+
 show_help=0
-run_time_sec=0
+run_time=0
 pause_time_sec=0
 link_name=''
+unit=s
 
-while getopts "h:n:r:p:" arg; do
+while getopts "h:n:r:p:SMHD" arg; do
    #echo "ARG[$arg] OPTARG[$OPTARG]"
    case $arg in
    n) link_name=$OPTARG
       ;;
-   r) run_time_sec=$OPTARG
+   r) run_time=$OPTARG
       ;;
-   p) pause_time_sec=$OPTARG
+   p) pause_time=$OPTARG
+      ;;
+   S) unit=s
+      ;;
+   M) unit=m
+      ;;
+   H) unit=h
+      ;;
+   D) unit=d
       ;;
    h) show_help=1
       ;;
@@ -115,12 +162,20 @@ while getopts "h:n:r:p:" arg; do
    esac
 done
 
-if [ -z "$link_name" -o $run_time_sec -eq 0 -o $pause_time_sec -eq 0 ]; then
+if [ -z "$link_name" -o -z "$run_time" -o -z "$pause_time_sec" ]; then
    show_help=1
 fi
 
 if [ $show_help -gt 0 ]; then
-   echo "Usage: $0 -n {CX name} -r {run time in seconds} -p {pause time in seconds}"
+   echo "Usage: $0 -n {CX name} -r {run time} -p {pause time}"
+   echo "   Use this on lanforge localhost"
+   echo "   time units are assumed to be seconds, or arguments to sleep(1)"
+   echo " $0 -n wanlink1 -r 10m -p 1-2s"
+   echo "   or time can be set for ranges with these switches: "
+   echo "   units: -S seconds, -M minutes, -H hours, -D days"
+   echo "   time can be a number or a range eg 1-10"
+   echo "   (units cannot be mixed if they are ranges)"
+   echo " $0 -n wanlink1 -r 10-20 -p 1-2 -M"
    exit 1
 fi
 
@@ -128,9 +183,7 @@ fi
 echo "Starting connection $link_name..."
 start_cx $link_name
 while true; do
-   sleep $run_time_sec
-   #echo "pausing..."
-   pause_wl $link_name $pause_time_sec
-   #echo "resumed"
+   sleep $(select_range $run_time)
+   pause_wl "$link_name" $(select_range $pause_time)
 done
 #