getopts allows you to accept command line arguments for the bash script, below is demo script which does following this, You can run the script as, bash scriptname.sh -h => it will display the help bash scriptname.sh -c => script displays “Good Morning / Good after noon/ Good Evening / Good NIght” if the time … Read more
Do you want to wait for an internet availability before proceeding further such as send an email from command line only when internet is available.. In those cases, we have to go into infinite loop of checking whether we are really connected to network. Ubuntu has a utility called “fping” we comes handy for such … Read more
Do you want to wait for an internet availability before proceeding further such as send an email from command line only when internet is available.. In those cases, we have to go into infinite loop of checking whether we are really connected to network. Ubuntu has a utility called “fping” we comes handy for such … Read more
The below shell script uses start-stop-daemon from “/sbin/start-stop-daemon” to execute the program during booting so that the process is started boottime. In the below example, DAEMON=$PWD/helloworld.bin shows that our program is helloworld.bin and is located in current directory from where the script is executed. The above script can be executed as “bash start_daemon.sh start” to … Read more
When you type something on linux shell, by default Linux save the commands what you type as history to “~/.bash_history” or /home/username/.bash_history file so that you can easily check what you have typed previously using “history” command. $ history | tail 1998 sudo apt-get install mdns 1999 sudo apt-get install mdns-scan 2000 sudo mdns-scan As … Read more
If you ever published any new post on to your blog / website, and are using rss feed, your website adds newly published post to rss xml based on date and time of publishing and this same URL remains forever with the same timestamp. Now, if you are using automated feed burners or email services … Read more
In bash script, if we want to comment a single line, we just need to add # at the start of the line, like below Now, but in certain scenarios we need to put multiple line comments, like some description of what the script is for, OR just need to disable some section of code … Read more
Following shell script does, check if android application is installed find an apk path uninstall if its already installed install new apk if application is not installed [bash] #!/bin/bash ADBPATH=/usr/bin/adb PACKAGE_NAME=my.app.helloworld LOCAL_DESKTOP_APK_PATH=$PWD/PACKAGE_NAME.apk IS_PACKAGE_EXISTS=`$ADBPATH shell pm list packages $PACKAGE_NAME` echo "pm list package returned: $IS_PACKAGE_EXISTS " if test -n "$IS_PACKAGE_EXISTS" then echo "Application $PACKAGE_NAME exists" CMD=`$ADBPATH … Read more
Android devices has a daemon adbd which helps it to get connected over USB using adb command on linux host. If you are doing some kind of automation such as taking logs or installing some applications from ubuntu command line, the very first thing we need to make sure if our device is connected and … Read more
Following shell script helps to understand how to use modulo operator in bash and identify if number is completely dividable by another number and print the remainder.This script accepts two arguments on the commands line, first number is Divident and second number is Divisor. $ vim understanding_modulo_operator.sh [bash] #!/bin/bash NUMBER=$1 DIVIDE_BY=$2 remainder=$((NUMBER%DIVIDE_BY)) echo "Module operation … Read more
