Shell Programming and Scripting

Is there any command which I can apply from the command line to find and replace a particular text say "00:00:00:00" with "00" from all the files( where ever this text exists) of the current directory?

Yes, but be warned this does ALL files in a given directory.
It also does not change files in subdirectories.

Code:

cd /directory/I/want/to/change
ls -1 * |
while read fname
do
   sed 's/00:00:00:00/00/g'  "$fname" > tmp.tmp
   mv tmp.tmp "$fname"
done

# For multiple files
perl -pi -e 's/searchterm/replaceterm/' *.txt

#for single file
perl -pi -e 's/searchterm/replaceterm/' myfile.txt

Or very similarly:

sed -i -e s/searchterm/replaceterm/g *.txt

You may need to quote the expression. You can also edit files in place with ed.

Thanks for the reply. But this command will just display the term replaced by the new term, not that the changes actually takes place in the file. Even if we redirect the output to a different file this can be done only for one file at a time and also getting back to the original file name is at the cost of another command.

isn't there any way the changes can directly take place in those files?

Thanks in advance

This is what the -i switch is for. From the sed man page:

Code:

 -i[SUFFIX], --in-place[=SUFFIX]

              edit files in place (makes backup if extension supplied)

This is GNU-ism - not all sed-s support that.