Shell like bash or sh are application which provide you a way to run other application/commands via the command line interface.
Most of the command and applications which you run (like vi, nano, ls, fsck etc) are separate applications, when you type in any of these commands the shell looks them up and runs them.
you can use a command called тАШwhichтАЩ to find out where a particular command file is located. (e.g. which ls will give you where ls command is)
BASH
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As an administrator/user of GNU/Linux you will be working on the command line one or the other time. There are hundreds of commands available in the system and each command has multiple options. Once in a while we need help on these command or sometime we need to find out if there is a command to do something which we want to get done.
As an administrator or GNU/Linux enthusiast you might come across a requirement of logging information from you shell scripts into files whenever they are run. We would love to do this if the files created have a unique name and also give out information when it was created.
In this post we will see how we can achieve that.
рдЧреНрдиреНрдпреВ/рд▓рд┐рдирдХреНрд╕ рдПрдбрдорд┐рдирд┐рд╕реНрдЯреНрд░реЗрдЯрд░ рд╣реЛрддреЗ рд╣реБрдП рдЖрдкрдХреЛ рдХрднреА рдирд╛ рдХрднреА рд╢реЗрд▓ рд╕реНрдХреНрд░рд┐рдкреНрдЯ рдХреЗ рдЬрд░рд┐рдП рдлрд╛рдЗрд▓ рдмрдирд╛рдиреЗ рдХреА рдЖрд╡рд╢реНрдпрдХрддрд╛ рдкрдбрд╝реЗрдЧреА рдЗрд╕ рдлрд╛рдЗрд▓ рдХрд╛ рдирд╛рдо рдпреВрдирд┐рдХ рд╣реЛрдирд╛ рдЪрд╛рд╣рд┐рдП рдФрд░ рдЗрд╕реА рдлрд╛рдЗрд▓ рдореЗрдВ рд╢реЗрд▓ рд╕реНрдХреНрд░рд┐рдкреНрдЯ рд╕реЗ рдЖрдк рдЗрдВрдлреЙрд░реНрдореЗрд╢рди рдХреИрд╕реЗ рд▓рд┐рдЦреЗрдВрдЧреЗ редрдЖрдЗрдП рдЗрд╕ рдкреЛрд╕реНрдЯ рдореЗрдВ рджреЗрдЦреЗрдВред
Some or the other time as a sys admin you will come across a need to add multiple users to your Linux system. So the question is how to do the same.
Let us see how we can do the same in this post.
We will assume that N number of users are to be added with a standard prefix or suffix and values incrementing with numbers. e.g. employee27... emp28.. etc
The command to add a user is useradd
The command can be simply run as:
BASH is the default shell in GNU/Linux systems. While writing BASH scripts sometimes it become necessary to take action based upon the success of previous command. So how do we do this.
First we need to understand that almost every command that is run once completed returns a exit code, 99% of commands just use 0 for success, 1 for failure. Without getting into other details, lets see how we can use this value.