Skip to main content

Other Commands


alias aliasname='command' creates a temporary macro aliasname that executes command
chsh changes the shell
clear clears the screen
crontab maintain crontab files for individual users
env <VARIABLE=value> sets environmental VARIABLE to value (blank to show all)
kill pid kills process pid. kill –9 pid to force kill (use ps to list pid)
newgrp group sets group as the primary group owner for new files created
nice -n priority command executes the command with a specified priority
renice priority pid changes a program's priority level afterwards (see nice, ps).
script logs everything that you type to . “exit” to quit.
sleep time makes the computer wait for time. Try “sleep 30; echo Go”
telinit level specifies which runlevel to run at (0 = halt, 1 = single-user, 3
= full multi-user, 5 = X-windows, 6 = reboot)
umask permission
changes the default file permission for new files (ex: rw-r—r--). umask 077 makes all new files rw------. The permission
that you set is subtracted from the default 666 permission (rwrw-rw) so that umask 022 does 666 – 022 = 644 = rw-r--r--)

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

Writing a Bash Shell Script

Bash shell scripts in Linux are text files that contain a series of commands that can be executed by the Bash shell. Bash (Bourne Again Shell) is a popular shell in Linux and UNIX systems, and shell scripts are used to automate tasks, configure systems, or perform a sequence of operations. How to Write a Bash Shell Script Create a New File: You can create a new script using any text editor like nano , vim , or gedit . gedit myscript.sh Write the Script: A basic shell script begins with a "shebang" ( #!/bin/bash ) to specify the interpreter that will be used to execute the script. The rest of the file contains the commands to be run. Example of a simple script: #!/bin/bash # This is a comment echo "Hello, World!" # Print "Hello, World!" #!/bin/bash : Specifies that the script will be executed using the Bash shell. echo "Hello, World!" : A command that prints the string "Hello, World!" to the terminal. Comments: Any line starting ...
Post a Comment
Read more

Different syntax for writing arithmetic expressions in bash shell

#!/bin/bash echo "Enter two numbers" read a b s=`expr $a + $b` echo "Sum1=$s" s=$[$a+$b] echo "sum2=$s" ((s=$a+$b)) echo "sum3=$s" ((s=a+b)) echo "sum3=$s" let s=$a+$b echo "sum4=$s" let s=a+b echo "sum4=$s" Note:bash shell support only integer arithmetic.zsh support operations on real numbers.We can use bc in bash shell to do real arithmetic. Eg: echo "$a*$b"|bc # where a and b are real Mathematical Operators With Integers Operator Description Example Evaluates To + Addition echo $(( 20 + 5 )) 25 - Subtraction echo $(( 20 - 5 )) 15 / Division echo $(( 20 / 5 )) 4 * Multiplication echo $(( 20 * 5 )) 100  % Modulus echo $(( 20 % 3 )) 2 ++ post-increment (add variable value by 1) x=5 echo $(( x++ )) echo $(( x++ )) 5 6 -- post-decrement (subtract variable value by 1) x=5 echo $(( x-- )) 4 ** Exponentiation x=2 y=3 echo $(( x ** y )) 8
Post a Comment
Read more

Basic Linux Commands For Beginner's

Basic Linux Commands for Beginners Linux is an Operating System’s Kernel. You might have heard of UNIX. Well, Linux is a UNIX clone. But it was actually created by Linus Torvalds from Scratch. Linux is free and open-source, that means that you can simply change anything in Linux and redistribute it in your own name! There are several Linux Distributions, commonly called “distros”. A few of them are: Mint Ubuntu Linux Red Hat Enterprise Linux Debian Fedora Kali Linux is Mainly used in Servers. About 90% of the Internet is powered by Linux Servers. This is because Linux is fast, secure, and free! The main problem of using Windows Servers are their cost. This is solved by using Linux Servers. Forgot to mention, the OS that runs in about 80% of the Smartphones in the World, Android, is also made from the Linux Kernel. Yes, Linux is amazing! A simple example of its security is that most of the viruses in the world run on Windows, but not on Linux...
4 comments
Read more