Hi guys this my sample file sample.ksh DBUID=testdatabase DBLOC=wm4r2 i want replace DBUID=testdatabase by DBUID=$myvariable (i.e myvariable=arundatabase). the name testdabase is not fixed and it changes from time to time. so my search criteria is DBUID. after replacing the line i need to save it in same file thus finally i want my sample.ksh file as DBUID=arundatabase DBLOC=wms4r2 this is how i want u to help u.. read the line from a file and replace it from mychoice data and save it back to the same file without altering the other contents. i m looking forward to your help.. get me the solution as soon as possible thanks Arun

#/bin/ksh myvariable=arundatabase sed "s/DBUID=.*/DBUID=$myvariable/" sample.ksh >/tmp/sample.ksh mv /tmp/sample.ksh . it's ok.