Looking for Something? How to grep Multiple Strings in Linux
As a Linux user, you may find yourself often needing to search for specific pieces of information within a file or a set of files. This can be a time-consuming task if you’re manually scanning through each file, but luckily the “grep” command exists to make it easier for you. Grep is a powerful tool that allows you to search for text within files, and with a few modifications, it can be used to search for multiple strings at once.
Here’s how to grep multiple strings in Linux:
1. First, open your terminal window and navigate to the directory where the files you want to search are located.
2. Next, type the command “grep” followed by the -e flag and the first string you want to search for. For example, if you want to search for the words “Linux” and “command”, you would type:
grep -e Linux file1.txt
3. To search for the second string, simply add another -e flag followed by the string. In our example, you’d type:
grep -e Linux -e command file1.txt
Note that you can continue to add additional -e flags and strings to search for as needed. If you have a long list of strings to search for, you can save them in a file and use that file as input to grep. Here’s how:
1. Create a text file called “strings.txt” and add each string you want to search for on a separate line.
2. Go back to the terminal and type:
grep -f strings.txt file1.txt
This tells grep to use the file “strings.txt” as the patterns to search for.
3. If you have multiple files in the directory that you want to search, you can use wildcards to specify the file name pattern. For example, if you want to search all files in the directory that have a “.log” extension, you can type:
grep -e string1 -e string2 *.log
This will search for both “string1” and “string2” in all files with the “.log” extension.