Quick Bytes IT Stuff

How to save the output of a command to a variable in Bash script? In Bash getting the output of a command line in terminal is sometimes necessary when doing Bash/Shell script. For example, if need to monitor a specific service whether it is installed, running or disabled. Getting the output of the command that checks the status of specific service is quite important, so the script will know on what to execute. If the specific output shows that the service has stopped then the script can decide to start the service, or if the output shows that a specific service or software is not installed then an option to install the software can be done. Here’s an example on how to save the status of a specific output to a variable using Bash. #!/bin/bash dcommand=$(systemctl status gdm.service) command_output=$(echo "$dcommand") str_running='Active: active (running)' if [[ "$command_output" == *"$str_running"* ]]; then   echo "It's the...

Strings are quite basic in any scripting or programming languages. If a journey to a thousand miles starts with a single step, in the programming world the journey starts with a string called “Hello World” and beyond “Hello World” pseudocode and algorithm will keep the journey going.   Strings in scripting or programming are just group of characters. So, if string is a group of characters then it can be slice by character or a sub-string can be taken from the string. To slice a string in Bash, a syntax which is part of the Bash library can be used. Syntax is: ${string_to_be_sliced:slice_start_position:slice_end_position} Example string: slicethestring=“Hello Algorithm World” The string is stored in a variable: slicethestring To get the sub-string “Algorithm World”. Code will be:   echo ${slicethestring:6:23} #start the slice at position 6 till position 23 Another way to slice the string from a specified start position till the end; is to tell Bash the star...

Finding accessed and modified files might be necessary at times to check or for audit purposes. If files kept in a folder or directory has been accessed or modified but should not be the case then something dubious is going on.  In Linux finding accessed and modified files can be done in a one liner command. find /home -type f -amin -60 || -mmin -60 -print Above command will find or show any files accessed within the last 60 minutes with the option "-amin" and it will show also the files modified within the last 60 minutes with the option "-mmin". A shell script can be created and further processing can be done when files are detected. The time can be adjusted if there's a need, but a more robust solution to check any accessed or modified files should be a file system watcher, but above command is quite helpful to check any activity that should not be occurring. Cheers..till next time!   ================================ Free Android Apps: Click  links below to f...

Knowing the devices in your computer is quite important in order to check what devices are installed or running in the computer Getting to use Linux or starting to use it may seem daunting for others. But Linux is awesome aside that its free and open source, in order to get used to it then you have to use it. How to check installed USB drives or external USB devices in Linux? How to check what graphic chipset or video chipset your computer is using in Linux? How to check the audio chipset in your Linux system? All these questions will pop-up once you start using Linux. Or how would to check whether the inserted USB thumbdrive or an external USB drive is detected or not. Well, some Linux distro provides a GUI interface to do it. But the very basic way to check is to open via the Terminal window. Or basically the command line in Linux. ls - or list directory contents is the most basic way to learn on command line ls will list the files a...

Search the whole directory:     find / -name "php.ini" -print     find / -name "owncloud.conf" -print Using whereis command:      whereis php.ini From man whereis (command): NAME        whereis  -  locate the binary, source, and manual page files for a com-        mand Using locate command:     locate php.ini From man locate (command): NAME        locate - find files by name To find out more, type at terminal:     info locate     info whereis     locate --help     whereis --help Cheers..till next time. ================================ Free Android Apps: Click on links below to find out more: Linux Android App cheat sheet: https://play.google.com/store/apps/details?id=com.LinuxMobileKit Multiplication Table for early learners ...

Adding Samba users to Linux Centos box or other Linux distro fails.  If a user account name, added to Samba does not have an account on the Linux box, then creation of the Samba user account will fail. So before adding user accounts to Samba, create an account for the user on the Linux box. Do these steps below: Adduser account to Linux: 1. adduser  'user_name' --- create a user account     adduser --system --no-create-home user_name man adduser - for more info adduser --help adduser --info  apropos adduser You may need to add sudo before the command if you're running Ubuntu. Or check the documentation of your Linux distro on how to add user account. Now that a user account has been created, add the user account to Samba.  2. smbpasswd -a user_name   (the user name that was created on Step 1) man smbpasswd - for more info smbpasswd --help smbpasswd --info apropos smbpasswd If everyth...

“Awk" command illustration on how to process input strings and get desired output. Example below shows how "Awk" manipulates the string to get the data needed. Below shows the output normal output listing of  "ls -l" command. Output of  "ls"  below has "9" columns separated by space in between the columns. "d" = In Linux if the listing starts with "d" it shows that the filename listed at the "9th" column or the last column is the name of the directiry. "-" = In Linux if the listing starts with "-" it indicates that the data is just a regular file or not a directory of course. Those are commonly used naming convention or indicators to determine the type of data. There are some other indicators used such as for symbolic links and hard links. [ttxers@farmx99 honey_store]$ ls -l total 16 drwx------ 3 branchx branchx 4096 Apr 26   2015 lists drwx------ 3 branch...

Copy a single file using robocopy from a local folder to a shared folder on the network. A simple rule of thumb before any disaster strike, don't interchange the source and the destination. If source and destination is mistakenly reverse, files might get overwritten. To avoid any loss of data do a test with a dummy file to ensure things work perfectly. Robocopy [source]    [destination]   [file to be copied] robocopy c:\local_c_folder  \\PC_network\shared_folder   file_to_be_copied_xx.txt The command will be completed successfully provided the network access right has no issues. Robocopy works quite good on large files. A simple copy or xcopy command will also work but the speed might vary. However, if the file (ex. an ISO file) and is more than 4GB and the filesystem  of the thumbdrive or the storage is FAT system, then robocopy or any methods of copying will not work. Since FAT has a file size limitation of less than 3GB. Roboco...

Set, update or change a user password in Samba. If domain admin or user password that is set on samba needs to be updated. Open terminal then update using the command below:      smbpasswd -a     smbpasswd -a administrator After pressing enter, type the password twice to validate and confirm the password. If the user name or admin password has been updated on the Windows Active Directory, then the Samba password has to be updated as well. If the samba password is not updated then the client from the windows environment authenticating to samba will not be able to connect to samba shares. To dig more about smbpasswd check out link below: https://www.samba.org/samba/docs/man/manpages/smbpasswd.8.html -a This option specifies that the username following should be added to the local smbpasswd file, with the new password typed (type for the old password). This option is ignored if the username following already exists in the smbpasswd file ...