search & replace

raj_sony2001 · 05-30-2006, 05:30 AM

I want to search & replace following string

'/etc/passwd |grep "^molis:"'

with

'/etc/passwd |grep "^wam:"'

in the entire directly

some please help in this

thank you

spirit receiver · 05-30-2006, 06:27 AM

Did you mean 'in each file in the current directory'? If so, the following should do:

Code:

for i in $( grep -l '/etc/passwd |grep "\^molis:"' * ); do sed -i.bak -e 's=/etc/passwd |grep "^molis:"=/etc/passwd |grep "^wam:"=g' $i; done

This will not only do your search & replace, but also create a backup of each changed file with the extension ".bak". But make sure that this won't overwrite any existing files you'd like to keep.

blackhole54 · 05-30-2006, 06:38 AM

There are multiple text editors available in Linux. Most people have their favorite editor or two. One (of probably several) editors that understand regular expressions is vi (or vim). Commands can be given to do the replacement in part or all of the file. If you use an intermediate, temporary file, you can also do what you want non-interactively using sed, a stream oriented editor. Check out the man pages ("man vi" or "man sed").

Since passwd is a system file, you will need to be running as root (superuser). If you are using the shadow passsword file (and you should be), you will need to modify that file too.

muha · 05-30-2006, 07:00 AM

I wasn't sure whether you wanted to include the quotes? (') I included them in this example:

Code:

sed -i.bak 's#\('"'"'/etc/passwd\ |grep\ "^\)molis\(:"'"'"'\)#\1wam\2#g' *

(copy and paste this, mind the quotes!)
This sed finds all strings
<everything>'/etc/passwd |grep "^molis:"'<everything>
and replaces.
It makes a backup of the original files because of the .bak option.
Without backups it would be -i
I you need more explanation of this command, post so. Cya!

ygloo · 10-05-2006, 02:05 PM

sed -i.bak 's/molis/wam/g' /etc/passwd