Unix replace string in files

Here I'm invoking it with the following parameters:. This is a little command-line utility that takes what receives in input and passes it as argument to another program.

So in this example the output of grep is passed to the next command sed as its argument. In the current snippet I'm using it to replace text with the following parameters:. Both grep and sed support regular expressions, so you can search with grep given a specific pattern and then replace the text with sed given another one. Take a look at the grep manual and the sed manual for more information.

StackOverflow - How to replace a string in multiple files in linux command line. Nope, thanks anyway. OpenSolaris Commands. Linux Commands. SunOS Commands. FreeBSD Commands. Full Man Repository. Advanced Search. Contact Us. Forum Rules. Mark Forums Read. Thread Tools. View Public Profile for pharos Find all posts by pharos View Public Profile for porter.

Find all posts by porter. Awk is a scripting language used for manipulating data and generating reports. The awk command programming language requires no compiling, and allows the user to use variables, numeric functions, string functions, and logical operators. Awk is mostly used for pattern scanning and processing. Click "Replace" in the File Controls Click on the down arrow on the far right of the file name to open the File Controls.

Click Replace. The Replace file pop-up window will appear. Click Browse to locate the new file on your computer. Select a file and click Open. Click Upload in the pop-up window. In the current snippet I'm using it to replace text with the following parameters: i — replace in file. The s stands for substitute i. Change characters The tr command in Linux is used to change characters. To change every occurence of the letter a in the file into the uppercase A , we can use the following command: We can specify more than one character to change:.

While echo is the default command xargs executes, you can explicitly specify any other command. For example, you can pass the find command along with its '-name' option as an argument to xargs , and then pass the name of the file or type of files you want to find to search as input through stdin. You may also redirect output from a command to grep using a pipe: Regex patterns are also supported by the -E option if you want to search for a set of strings rather than one literal:.

For a different field separator : in this example use:. NOTE: both the awk and perl solutions will affect spacing in the file remove the leading and trailing blanks, and convert sequences of blanks to one space character in those lines that match. If you have a large number of patterns, it is easier to save your patterns and their replacements in a sed script file:.

That will be quite slow for long lists of patterns and large data files so you might want to read the patterns and create a sed script from them instead. The method is very general though: basically, if you can create an output stream which looks like a sed script, then you can source that stream as a sed script by specifying sed 's script file as - stdin.

When working with fixed-strings as patterns, it is good practice to escape regular expression metacharacters. You can do this rather easily:. A good r e pl acement Linux tool is rpl , that was originally written for the Debian project, so it is available with apt-get install rpl in any Debian derived distro, and may be for others, but otherwise you can download the tar.

Note that if the string contains spaces it should be enclosed in quotation marks. By default rpl takes care of capital letters but not of complete words , but you can change these defaults with options -i ignore case and -w whole words. You can also specify multiple files :. Or even specify the extensions -x to search or even search recursively -R in the directory:.

Finally, if you are unsure what exactly will happen, use the -s simulate mode. How to do a search and replace over multiple files suggests:. Update: The above result will fail on filenames that contain whitespaces. Instead, use:. For example,. A nice feature is that qsubst will do a query-replace , i. How to get it: qsubst was invented by der Mouse from McGill and posted to comp. Updated versions exist. For example, the NetBSD version qsubst.

See Rust regex documentation for regular expression syntax and features. Like grep , the -F option will allow fixed strings to be matched, a handy option which I feel sed should implement too. I needed something that would provide a dry-run option and would work recursively with a glob, and after trying to do it with awk and sed I gave up and instead did it in python.

The script searches recursively all files matching a glob pattern e. Every long option such as --search-regex has a corresponding short option, i. Run with -h to see all options. Here is an updated version of the script which highlights the search terms and replacements with different colors. Here I use grep to tell if it is going to change a file so I can count the number of lines changed, and replacements made, to output at the end , then I use sed to actually change the file.