nestgift.blogg.se - Bash grep all files in directory

If you do not have a Linux distro set up, you can use an online command shell to practice these commands.įor this tutorial I used the terminal found on MacOS.

You can use a Linux shell or any Unix terminal like the one found on MacOS.

In this tutorial you will use the grep command to search within files and directories and print file types that contain a certain string and more. There are many ways to use the grep command. It would print all the lines matching a certain pattern. It was a command used in a simple Unix text editor called ed(pronounced ee dee). Without it just the file name appears: printf "%s" ABC*Īssuming you run the command within the directory in which the files exist.Grep is a commonly used command in Linux (or Unix) to search through 1 or more files for a pattern or word.įun fact: grep is short for Global regular expression print(g/re/p). "/path/to/files/" remains in the output if you entered it that way when you ran the 'printf' command. If you need line breaks after each instance: printf "%s\n" /path/to/files/ABC* Returns: /path/to/files/ABC /path/to/files/ABC123 If you going to use this in a script the output of 'printf' will not contain a new line character until the end of the output stream as such: printf "%s" /path/to/files/ABC* In that case using 'printf' with glob pattern matching is considered safe. From the command line using 'ls' in place of 'printf' here is a safe alternative however, depending on who's opinion you agree with, 'ls' is not safe for use in a script. This will match all occurrences of files starting with "ABC" such as "ABC", "ABC.txt", "ABC123", but not "xABC". This is glob pattern matching which is anchored at both ends.

If files were created today you must run sudo updatedb first.In comparison the find command starting at / root directory will a very long time and generate many permission errors.The above command takes 1 second to run on 1 million files.mnt/old/home/rick/.cache/mozilla/firefox/fault/cache2/entries/ABC0C99FCEABAD0C6AA2078CD025A1CDE48D7BA1 mnt/clone/usr/src/linux-headers-5.0.1-050001/tools/lib/lockdep/tests/ABCDBDDA.sh mnt/clone/usr/src/linux-headers-5.0.1-050001/tools/lib/lockdep/tests/ABCDBCDA.sh If you don't know the directory the ABC* files are located in, and you have millions of files, the locate command is the fastest method. (Yeah, matching any character would be harmless in our case, but I did it for completeness' sake.) In case you want to use it as a literal dot, you'll have to "escape" it using a backslash \ before it. in regex has a special meaning too: it means "match any single character here". ^ in regex matches the beginning of the string this prevents it from matching the pattern if it doesn't occur in the beginning of the file name. Regex is an extremely powerful searching tool if you master it, and there are sites such as this which teach you about it in more depth, but note that grep is not a full-fledged regex engine and you can't do everything with it. Now the pattern itself is written in a particular syntax called regular expression, or regex for short. Notice that the pattern is quoted with single quotes ' ' to prevent the shell from interpreting the special characters inside it.Grep takes the output and filters it using the given pattern, ^\./ABC. The pipe character | redirects the output of one command to another, in this case the output of find is redirected to grep.

Being aware of this is important because it means we will search for results starting with. , indicating that their path is relative to the current directory.

Note that find outputs each file or directory starting with. To understand the command, let's break it down a bit:įind lists all files under the current directory and its sub-directories using it alone will just list everything there. Generally, if you want to just list them, you can do it in a terminal using: There are many ways to do it, depending on exactly what you want to do with them.