Help

stardotstar · 10-14-2004, 06:38 PM

I have managed to hang the Gnome simple text editor conducting a find and replace operation on a large mysql database.

The sql is about 40MB and I want to search for table names and replace them.

It is an extremely simple operation simply find `xyz_` and replace with `abc_`

I am very inexperienced with Vi and only use it for editing my conf files usually. I understand it is probably the best tool for this and shouldn;t crash out like gedit did.

Any help appreciated. BTW I have scrolled through lots of the help in Vi but the command structure and processes do not make sense to me yet.

Will.*

neo77777 · 10-14-2004, 06:48 PM

In command mode (press Esc key to make sure you are not in insert/edit mode) type
:%s/pattern/substitute_pattern/
Where pattern is the string you want to replace and substitute_pattern what to replace it with.
after it's done just save the file with
:wq!

CroMagnon · 10-14-2004, 06:49 PM

OK, it is possible to do in vim, but I wouldn't say it's the best tool for the job - the best tool would be sed

In vim, make sure you're in command mode (press ESC a couple of times), and then type:
:%s/xyz_/abc_/g
the colon is for a command, the % is for a range (means the entire file - you could do this over specific lines if you wanted). Everything else is like a sed regex.

To do it with sed on the command line, you could type this:

sed -ie "s/xyz_/abc_/g" sqlfile

you could expand the regular expression to be more specific if xyz_ appears in places you don't want changed.

darthtux · 10-14-2004, 07:00 PM

The problem with sed is it outputs to the screen. It can mess things up if you just try to direct it to a file because it reads and outputs line by line. I have created a shell script to alleviate hassles for me.

You specify script name and any files you want to do the search and replace on. It will prompt for string to replace and then the string you want to replace with. It places output in a temporary file, when sed is finished, it moves back to original file name and removes the temp file.

Code:

#!/bin/bash
# To replace every occurrence of string in all files specified as arguments

echo "Enter text to replaced"
read arg1
echo "Enter text to replace with"
read arg2
for i in "$@"; do 
cat $i | sed "s/$arg1/$arg2/g" > $i.temp
mv $i.temp $i
done

CroMagnon · 10-14-2004, 07:18 PM

darthtux: check out my command line again, and check out -i in the manpage

You might want to write "Kick me" in the comments to your script (I know I did before I found -i)

darthtux · 10-14-2004, 07:33 PM

CroMagnon, seems like I learn something new every day

But I still like to put things in scripts. The easier the better

especially if you search and replace qutie a bit.

stardotstar · 10-14-2004, 10:20 PM

This is great advice and very straightforward and helpful. Thanks all - I will try it now.

Will

idaho · 10-14-2004, 11:31 PM

A good way to get a handle on vi is to run the tutorial: vimtutor