operating systems HowTo - Linux / Unix Q & A from nixCraft

HowTo: Reverse a String In Unix / Linux Shell?

last updated July 6, 2012 in BASH Shell, Perl, UNIX

How do I reverse lines of a file or files under Linux or Unix like operating systems?

Bash Shell Script To Test For Empty Folder

last updated July 6, 2012 in BASH Shell

How do I check if a directory contains files? How do I find out if a directory contains files using bash shell under Linux or Unix like operating systems?

Linux / Unix: Generate A MD5 String

last updated October 4, 2013 in Cryptography, Linux, UNIX

I need to generate a md5 hash for given string. It will be used by shell script to generate keys for remote web service or cryptographic application. How do I generate a md5 hash based on any input string under Linux or Unix like operating systems?

Linux / Unix: Find Inode Of a File Command

last updated June 21, 2012 in Linux

How do I find out an inode (index-node) of a file under Unix like operating systems?

Unix / Linux Shell: Get Third Field Separated by Forward Slash (/) Delimiter

last updated April 29, 2012 in BASH Shell

I‘m writing a shell script for automation purpose. The output the path of the current working directory is stored in $PWD or it can be obtained using the pwd command. How do I find out find out 3rd field separated by the forward slash (/) delimiter using $PWD under Unix like operating systems?

Bash Shell: Check File Exists or Not

last updated April 20, 2012 in BASH Shell

How do I test existence of a text file in bash running under Unix like operating systems?

HowTo: Iterate Bash For Loop Variable Range Under Unix / Linux

last updated April 20, 2012 in BASH Shell

How can I iterate bash for loop using a variable range of numbers in Unix or Linux or BSD or Apple OS X operating systems?