UNIX for Dummies Questions & Answers

Hi

I am very new to linux and scripting.

I need to replace numbers abc with number xyz inputting from a reference file.
I used the following command -
sed "s/$grd/$lab/" , where $grd and $lab comes from reference file.

The problem is the above line doesnt take care of space..
eg- 1546745 12344 123
if i need to replace 123 with 666 => grd = 123, lab = 666
following is the result -
1546745 66644 666
THe required result is - 1546745 12344 666

the script shud recognise spaceNumberspace and then replace only.

Any help wud be appreciated.

Thanks,
Aj

so in grd you are storing 123 byu stdin or what??
if not write grd=" 123" and lab=" 666" will solve your problem i guess