How To Join Lines In Linux

Today, we explore a key concept in Linux – how to join lines. This operation can be useful in numerous situations, such as data transformation, file writing or scripting. So let’s dive in!

The ‘tr’ Command

Our journey begins with the tr command, which can replace or squeeze repeated characters. To join lines, we’ll utilize the -d switch that deletes specified characters. In this case, it will delete all newline characters.

The syntax for joining lines using the tr command is as follows:

    tr -d '\n' < file

The ‘paste’ Command

Next up is the paste command, which merges lines of files. It’s a simple and straightforward way to join lines in Linux, and here’s how to use it:

    paste -sd' ' file

The ‘awk’ Command

The awk command is a powerful tool for text processing. By manipulating the Output Field Separator (OFS) and the Output Record Separator (ORS), we can join lines in a file. Here’s the syntax:

    awk 'BEGIN {ORS=" "} {print}' file

The ‘sed’ Command

Finally, we have the sed (Stream Editor) command. This is another powerful text processing tool that we can use to join lines:

    sed ':a;N;$!ba;s/\n/ /g' file

With the sed command above, ‘:a’ creates a label ‘a’, ‘N’ appends the next line to the pattern space, ‘$!ba’ branches to label ‘a’ if it’s not the last line, and ‘s/\n/ /g’ replaces all newline characters with spaces.


Joining lines in Linux is a fundamental operation that comes in handy in various scenarios. It’s a versatile skill that every Linux user should have in their toolbox. With the tr, paste, awk, and sed commands, you can join lines in no time. Happy coding!