To look up all the files in a directory and sub-directory for a particular pattern or word, use: $ grep -R įor instance, the following command will list all the files that contain the word “Hello” in the Documents directory. If you want to look for lines that have one or multiple letters in them, use the following syntax: $ grep “” įor instance, the following command print all the lines that contain any letter from “a” to “f”. Matching lines that contain certain letters $ grep $ įor instance, the following command will print all the lines that end with “ t”. To print lines that end with a particular pattern, add “ $” to your command. $ grep ^ įor instance, the following command will print all the lines that start with “ Th”. To print lines that start with a particular word, add “ ^” to your command. Matching lines that start with a particular word $ grep –w įor instance, to search the exact word “ do” in the Donuts.txt file, the command would be: $ grep -w do Donuts.txtĪs you can see, it now only prints the line that contains the exact word “ do”. To match the exact word, add “ -w” to your command. We searched for the string “ do” and can see all the lines that contain “ do”. To print all the files in your current directory that match your pattern, use the following syntax: $ grep -l “” *įor instance, the following command will print all the files that contain the word “Hello”: $ grep -l “Hello” *īy default, grep prints all the words that match your pattern, even if they are part of a word. $ grep -n įor instance, the following command will print both the line number and the line that contains the word “Donuts”. To print both the line number and line that contains the matching word, add “ -n” to your command. Printing line number of matching pattern and lineīy default, grep prints the entire line that contains the pattern. $ grep -o įor instance, the following command will print only the word “Donuts” instead of printing the entire line from the file “Donuts.txt”. To print just the matching word, add “ -o” to your command. Use the following syntax to do so: $ grep -v įor instance, the following command will print all the lines except the one which contains the word “Donuts” in it.īy default, grep prints the whole line that contains the pattern. With Grep, you can also print the lines that don’t match your pattern by adding “ -v” to your command. Printing lines that do not match a pattern įor instance, to find all “.jpeg” files in the “Downloads” folder, the command would be: $ ls ~/Downloads | grep. Use the following syntax to do so: $ ls ~/ | grep. You can also find a file in a specific directory by its extension. To ignore the case, you will need to add “ -i” to your command like this: $ grep –i įinding a file by extension in a directory If we again run the above command with “donuts”, you will see no output this time. Grep performs case-sensitive searches by default, this means that it treats “Donut” and “donuts” differently. $ grep Donuts Donuts.txt cakes.txt Ignoring case $ grep įor instance, the below command will look for the word “Donuts” in both “Donuts.txt” and “cakes.txt”. You can also search for a specific word in multiple files. The syntax would be: $ grep įor instance, the below command will look for the word “Donuts” in the file “Donuts.txt”. With Grep, you can search any word in a specific file. The basic syntax of the Grep command is as follows: $ grep PATTERN Using Grep Command Finding a word in a file In case your system does not have Grep installed, you can install it using the below command in Terminal: $ Sudo apt-get install grep Most Linux distributions including Ubuntu 20.04 LTS come with grep installed. The same Grep commands also work for Debian, Mint, Fedora, and CentOS. The commands discussed here have been tested on Ubuntu 20.04. In this post, we’ll be looking at how to use the Grep command in Linux. It searches with regex, or regular expressions and prints lines from a file that matches the given pattern. It can look through files and directories, and read input from commands as well. Grep, or Global Regular Expression Print, is an extremely useful Linux command for finding matching patterns.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |