How to create and write data into files in Linux

This article explained how to create and write data into files in the Linux and Unix flavors. By using different types of commands we can create the files and we can write the data into files.

Create Empty Files

touch

using the touch command, we can create the empty file

touch /tmp/sample.txt

Create Files via vi editor command

Using the vi editor command-line tool, we can create empty or data files.

vi /tmp/sample.txt

Create and Writing data into files

Using the below command to create and write the data into a file.

Syntax
command > /tmp/sample.txt

Example
ls > /tmp/sample.txt

 

Append data into the file

Syntax
command >> /tmp/sample.txt

Example
ls >> /tmp/sample.txt

Sample data writing
echo "--------------" >> /tmp/sample.txt
echo "Domain information" >> /tmp/sample.txt
host www.narayanatutorial.com >> /tmp/sample.txt
echo "--------------" >> /tmp/sample.txt

Save the output of a command to a file

The tee command reads from standard input and writes to standard output and files.

The syntax is as follows for writing data into the file:

Syntax
command | tee /tmp/sample.txt

Example
ls | tee /tmp/sample.txt
date | tee /tmp/sample.txt

Append the data into the file

Syntax
command | tee -a /tmp/sample.txt

Example
ls | tee -a /tmp/sample.txt
date | tee -a /tmp/sample.txt

Here -a append the data into a file.

 

Comand	Description	Overwrite existing file?
command > sample.txt	Save terminal output (standard output) to a file named sample.txt	Yes
command >> sample.txt	Append terminal output (standard output) to a file named sample.txt	No
command	Takes standard input from sample.txt file	N/A
command 0	Takes standard input from sample.txt file	N/A
command 1> sample.txt	Puts standard output to sample.txt file	Yes
command 1>> sample.txt	Appends standard output to sample.txt	No
command 2> sample.txt	Puts standard error to sample.txt	Yes
command 2>> sample.txt	Appends standard error to sample.txt file	No
command &> sample.txt	Puts both standard error and output to sample.txt	Yes
command > sample.txt 2>&1	{POSIX} Puts both standard error and output to file named sample.txt	Yes
command &>> sample.txt	Appends both standard error and output to file named sample.txt	No
command >> sample.txt 2>&1	{POSIX} Appends both standard error and output to file called sample.txt	No
command | tee sample.txt	Puts standard output to sample.txt while displaying output on screen	Yes
command | tee -a sample.txt	Appends standard output to sample.txt while displaying output on screen	No
command |& tee sample.txt	Puts both standard output and error to sample.txt while displaying output on terminal	Yes
command 2>&1 | tee sample.txt	{POSIX} Puts both standard output and error to file named sample.txt while displaying output on terminal	Yes
command |& tee -a sample.txt	Append both standard output and error to file called sample.txt while displaying output on terminal	No
command 2>&1 | tee -a sample.txt	{POSIX} Append both standard output and error to file named sample.txt while displaying output on terminal	No