#SEARCH FOR TEXT IN FILES BASH HOW TO#
However, this article only covers how to use Bash interactively. Shell scripts provide an easy way to automate tasks. Bash provides us with many tools and commands that make us more productive while navigating and using our computer.Īnother popular use-case for Bash is for scripting. Despite the ubiquity of GUIs, interacting with a computer via a CLI is extremely useful for users, especially for administrative and programming tasks.īash (Bourne Again SHell) is arguably the most popular shell program. Before GUIs existed, users would interact with a computer via shell programs, a Command Line Interface (CLI) to run other programs. If you know exactly what you need to change, and you are dealing with a string that is safe to be replaced by another, you can speed up the process by using the commands shown here.īe extra careful with strings that may be common in your files: If you apply a global change that affects more than what you intended, you may have to revert to your backup copies (which you certainly have, right?).The most common interactions with a computer nowadays are done through a Graphical User Interface (GUI). The xargs command will receive each file name returned by the find command and apply the sed command. In this case, I use the find command with the parameter -type f to return only files and not directory names. type f | xargs sed -i 's/user_/admin_/g' For that, I use the find command again: find. In my example scenario, there are files in subdirectories that also need to be changed. Change strings in files in the current and subdirectories
The /g at the end of the parameter means replace all occurrences in each file. Here, I used the sed command with the -i argument to make the changes in place.
If I only wanted to change the strings in the files in the present directory, I could use: sed -i 's/user_/admin_/g' *.yml Change strings in files in the same directory Yes, regular expressions can get complex.įollowing are two ways you can change strings in multiple files simultaneously. In other scenarios, you may have to use regular expressions more elaborate than the example above to catch strings preceded by a comment ( #) followed by zero or more spaces or a mix of upper and lower case. Note: As the combination of find and xargs grep does not highlight the string user_ like in the first example, I added an extra grep command to highlight the string. In my example scenario, I have three files that contain references to variables user_name and user_home, which for some good reason I must change to admin_name and admin_home.īefore making any changes, I inspect the occurrences in the current directory:
Think of the following examples as methods to perform these types of changes using only the command line instead of an IDE.īut you may also want to inspect the changes before applying them because-different from the IDE option-the command-line method is more immediate (no confirmation is asked, by default). In this case, you would have the option to confirm, case by case, which occurrence to replace (unless you are pretty sure that you really want to replace all). If you are using an integrated development environment (IDE), you probably already have a function for global search and replace in multiple files.