bash hacks

commands to make for small, perhaps even simple, but very powerful utility

8 cards·by perchslayer

bashcommand linelinuxcommandshacks

How to sort an unsorted list of data with duplicate entries and generate a nicely formated report from the result.

cat unsorted_list_with_dupes.txt | sort | uniq | pr | lpr

How to Input a poorly formatted text file and dress it up for read and printability.

cat poorly_formatted_report.txt | fmt | pr | lpr

How to input a text file of a list of unsorted items and generate a sorted list text file.

[me@linuxbox me]$ sort < file_list.txt > sorted_file_list.txt

How to display a list of directories and how much space they consume, sorted from the largest to the smallest, using pipes

du | sort -nr

How to display the total number of files in the current working directory and all of its subdirectories, using a pipe.

find . -type f -print | wc -l

How to display the 10 newest files in the current directory, using a pipe.

ls -lt | head

What is "grep" and what does it do ?

A FILTER command that examines each line of data it receives from standard input and outputs every line that contains a specified pattern.

What is "uniq" and what does it do ?

A FILTER command, given a sorted stream of data from standard input, it removes duplicate lines of data (makes sure every line is unique).