replacing words in txt file ?

[haneo]

i want to replace the expression "/usr/local/mrtg-2/bin//mrtg" with this "/usr/bin/mrtg"

here is a part of my file:

/usr/local/mrtg-2/bin//mrtg /home/mrtg//ens1/ens1.cfg > /dev/null 2>&1
/usr/local/mrtg-2/bin//mrtg /home/mrtg//ens2/ens2.cfg > /dev/null 2>&1
/usr/local/mrtg-2/bin//mrtg /home/mrtg//ens3/ens3.cfg > /dev/null 2>&1

who can i do it ?

Thanks

 

[cyoung]

Try using sed. (the Stream Editor). This works really well, and is reasonably easy to use. (man sed).

Good Luck!

 

[CaKiwi]

Try this (untested) command.

sed 's#/usr/local/mrtg-2/bin//mrtg#/usr/bin/mrtg#' infile > outfile

Add a g before the closing ' if the string can appear more then once on a line and you want to replace all occurrences. CaKiwi

 

[quagsire]

Try using the following awk :
cat infile | awk '{while (sub("/usr/local/mrtg-2/bin//mrtg","/usr/bin/mrtg",$0)==1); print($0)}' >outfile