Bash delete line file containing string

Collectives on Stack Overflow. Learn more. Asked 9 years, 5 months ago. Active 6 years, 4 months ago. Viewed 18k times. Sara Sara 2, 10 10 gold badges 45 45 silver badges 76 76 bronze badges. Add a comment. Active Oldest Votes. This is because of the backticks. Similarly, deleting the line containing the specified string in the text file is also one of the operations we often use. This article will share with you how to delete lines in a text file that contain specified strings. There are multiple ways to delete the line containing the specified string in a text file: sed command , awk command and grep command.

The sed command removes the lines from m to n in the file. Delete lines other than the first line or header line Use the negation! The following sed command removes all the lines except the header line. Delete first and last line You can specify the list of lines you want to remove in sed command with semicolon as a delimiter.

However, this sed do not remove the lines that contain spaces. Sed Command to Delete Lines - Based on Pattern Match In the following examples, the sed command deletes the lines in file which match the given pattern.

Above sed command removes all the lines that start with character 'u'. The above command deletes all the lines that end with character 'x'. Note : In all the above examples, the sed command prints the contents of the file on the unix or linux terminal by removing the lines. However the sed command does not remove the lines from the source file. To Remove the lines from the source file itself, use the -i option with sed command. Tags Unix. Here's my solution:. This is fast because tail starts reading from the end, and dd will overwrite the file in place rather than copy and parse every line of the file, which is what the other solutions do.

NOTE: This removes the line from the file in place! Make a backup or test on a dummy file before trying it out on your own file! To remove the last line from a file without reading the whole file or rewriting anything , you can use. To remove the last line and also print it on stdout "pop" it , you can combine that command with tee :. These commands can efficiently process a very large file. This is similar to, and inspired by, Yossi's answer, but it avoids using a few extra functions.