Hey dudes,
what's the best way to do this? i'm no command line warrior, but i was thinking there's possibly a way using grep and cat.
i just want to replace a string that occurs in a folder and sub-folders. what's the best way to do this? i'm running ubuntu if that matters.
-d
find . -type f -print0 | xargs -0 -n 1 sed -i -e 's/from/to/g'
The first part of that is a find command to find the files you want to change. You may need to modify that appropriately. The "xargs" command takes every file the find found and applies the "sed" command to it. The "sed" command takes every instance of "from" and replaces it with "to". That's a standard regular expression, so modify it as you need.
As Paul said, you want to first find the files you want to edit and then edit them. An alternative to using find is to use GNU grep (the default on Ubuntu), e.g.:
grep -r -l from . | xargs -0 -n 1 sed -i -e 's/from/to/g'
You can also use ack-grep (sudo apt-get install ack-grep or visit http://petdance.com/ack/) as well, if you know you only want a certain type of file, and want to ignore things in version control directories. e.g., if you only want text files,
ack -l --text from | xargs -0 -n 1 sed -i -e 's/from/to/g'
An alternative to using sed is to use perl which can process multiple files per command, e.g.,
grep -r -l from . | xargs perl -pi.bak -e 's/from/to/g'
Here, perl is told to edit in place, making a .bak file first.
You can combine any of the left-hand sides of the pipe with the right-hand sides, depending on your preference.