Bash

Using sed with a command: Use sed with the a command to add a line to the file’s end in Bash. This is line 1. This is line 2. This is line 3. sed -i '$a\This is the last line' myFile.txt In this example, the sed command is used with the a option to add […]

Bash Sort CSV by Column Using sort Command Use bash’s sort command to sort the CSV file by column. Name,Age,City John,25,New York Alice,32,San Francisco Michael,28,Chicago Emily,22,Los Angeles #!/bin/bash sort -t',' -k2 myFile.csv Emily,22,Los Angeles John,25,New York Michael,28,Chicago Alice,32,San Francisco Name,Age,City In this example, the sort command is used to sort the myFile.csv file by column. […]

Using echo Command Use the echo command with redirection operator (>) to write variable to file in Bash. #!/bin/bash greetings="Welcome to Java2Blog!" echo $greetings > results.txt cat results.txt Welcome to Java2Blog! Use the echo command with the append operator (>>) to append a variable to the end of the specified file in Bash. #!/bin/bash greetings="Welcome […]

Using Shorthand Operator Use the Shorthand operator to append one element to an array in Bash. #Declare an array my_array=("element1" "element2" "element3") #Append a new element my_array+=("new_element") #Print the array echo "${my_array[@]}" element1 element2 element3 new_element First, we declared an array (my_array) with three initial elements element1, element2, and element3. Then, we used the shorthand […]

Using cUrl command with -w, -s and -o options For Get Method Use the -w or --write-out option in combination with the %{http_code} format specifier to get curl response code in Bash for get method. #!/bin/bash response_code=$(curl -s -o /dev/null -w %{http_code} 'https://www.google.com') echo "Response code: $response_code" Response code: 200 We can also rewrite it […]

Using sed Command Read the provided text file and remove lines containing string using sed command. We will not modify the input file (file.txt) but display the output on the Bash console. We can use -i option in case we want to modify input file This is line number one. It's line two. Here is […]

Using awk command with sub() method Use the awk command with sub() method to remove the first column from the given CSV file (inputFile.csv) in Bash. We will not update the input file but display the output on the Bash console. index,firstname,lastname 1,John,Williamson 2,Nancy,Paul 3,Martin,Guptill 4,Adam,Douglass 5,Sam,Brown awk -F, '{$1="";sub(/,/,"")}1' OFS=, inputFile.csv firstname,lastname John,Williamson Nancy,Paul […]

1. Overview In Unix-like environments, especially in scripting and programming with Bash, there might be scenarios where we need to remove the last line from a file. This operation is typical in data processing, log file management, and scripting. 2. Introduction to Problem Statement Imagine we have a text file named test.txt containing the following […]

Using sed Command Use the sed command to remove spaces from string without updating the original variable in Bash. var=" Java 2 Blog " echo $var | sed 's/ //g' Java2Blog First, we stored the string value in the var variable. Then, we piped it to the sed command, a stream editor performing operations on […]