Recursive text substitution in multiple files is not a task that the average end user is called upon to perform very often. But lets suppose that you have a couple of web sites either with a hosting company or on your own server. Let us suppose further, that you want to change the mailto link address on every page on your site. Not a problem if you only have 5 or 6 pages but what if you have five or six hundred? Clearly, in the absence of an automated text replacement utility, you are going to be spending a lot of quality time with the WISYWIG editor of your choice.
Of course you could always employ the venerable 'sed' command with 'find' and 'exec' but that has limitations and the syntax is possibly the most bizarre and grotesque construction in the whole of Unix! Here is an example:-
find ./path/to/directory -type f -exec sed -i 's/oldtext/newtext/' {} \;
Enter 'rpl'!! The program was written for Debian as a free replacement for the non-free rpl program by Joe Laffey which can be found here. Rpl defines its function in the following terms (from the manual):-
"Basic usage is to specify two strings and one or more filenames or directories on the command line.The first string is the string to replace,and the second string is the replacement string."
One of the joys of 'rpl' is that it will replace text recursively by simply specifying the -R option. If you are running Ubuntu/Debian 'rpl' is available from the repositories. It is of course a command line tool but the man page is amongst the most intelligible and comprehensible that I have ever read.
In keeping with the spirit of this series of articles I could not resist writing a 'Dialog' front end for the 'rpl' program which allows the user to deploy some of its most useful functionality from the GUI. Here is the help file included with the script:-
OPTION 1. prints this help file - OPTION 2. will replace all instances of a text string with a new string in a given file - OPTION 3. will replace all instances of a text string with a new string in all files in a given directory. - OPTION 4. will replace all instances of a text string with a new string in all files in a given directory and all its sub-directories. WORKS WITH TEXT AND HTML FILES ONLY! You will need to enter the full path to all files and folders. This front end script should work equally well for single and multiple word substitutions . RPL is a command line program and it is capable of much more than this. In order to acquaint yourself with the full range of its capabilities consult the manual - man rpl. Enjoy!
As you can see the script allows you to replace text in a single file; in a group of files in a directory or in an entire directory tree. Having access to a tool like this can save hours of arduous labour with an HTML editor. In order to make this work you will need to install 'dialog' and 'rpl'. They are both in the Debian/Ubuntu repositories. I have tested this fairly extensively and it seems to work OK. if you find otherwise please let me know so that I can fix it. Enjoy!
Script here
