UNIX for Dummies Questions & Answers

Hello all,

I'm working on a foreach loop to compare a couple sets of data. However, each datafile includes a header row. I'm wondering if it is possible to tell the foreach loop to skip the first line of data.

I've been using the basic code as follows:

foreach line ("`file.csv`")
set some variables
do stuff
end

I suppose I could probably throw an if statement in there (e.g., if the first element of the line is the first element of the header, continue; else, do stuff), but I'm not really sure how to write that, either.

Thanks for your help.

That's a useless use of backticks and, if you'd managed to get it to work at all, would have been a useless use of cat too. That's a ticking timebomb in a variety of ways -- if your file's bigger than 4K that loop will blow up on many systems. If your data ever might have spaces in it, it will occasionally split in places you didn't want it to. And on.

while read is safer and more efficient.

Code:

exec 5<filename # Open file into FD 5
read SKIP # Read and ignore the first line from FD 5

while read LINE
do
...
done <&5 # Read from FD 5
exec 5<&- # Close FD 5

Thanks a lot... I'll give this a shot!