Here the output of the grep command becomes the input of the wc command. The pipe is used to send the standard output of the command before the pipe to the standard input of the command after the pipe. We can use the grep command followed by the wc command using the pipe. Now, let’s say we want to count the number of errors in the same file.

Counting the Occurrences of a Pattern in a File The -l flag is used to get the number of lines, the reason for this flag is that the wc command allows to do a lot more than just counting lines…Īs you can see in this case the number of lines in the file is 2094. To count the number of lines we will use the following syntax: wc -l wc -l /var/log/messages This file contains global system messages and it’s very useful to troubleshoot issues with your Linux system. Let’s say we want to count the lines in the /var/log/messages file. The most used command to do that is the wc (word count) command. Let’s find out how! The Linux Command to Count Lines So, how can you count the lines of a file using Linux? These are just two examples of scenarios in which you need to be able to count the lines of a file. How many errors can you see in the logs of your application? How many unique users have used your application today? It can be very useful in many circumstances, some examples are: getting the number of errors in a log file or analysing the output coming from other Linux commands. Linux provides the wc command that allows to count lines, words and bytes in a file or from the standard input. How to count the lines in a file with Linux? Knowing how to count the lines of a file or from the output of a command is a must in Linux.

Ls grep file extension