Line matching with sed

[Declan Heerey]

Hello,

I am trying to run sed against a file (200 lines long) where the first three characters of the file should always be HDR, POL and OBJ. What i want is to run sed on the file, check the three first characters of each line and if it is not HDR, POL or OBJ then error out! Can anyone help, it'd be much appreciated!

[Justo Exposito]

Hi Declan,

I Think that is better to use grep for this job, for instance:

grep -v -e "^HDR" -e "^POL" -e "OBJ"

Regards,

Justo.

[Justo Exposito]

Sorry mismatch

grep -v -e "^HDR" -e "^POL" -e "^OBJ"

Regards,

Justo.

[Steve Steel · Accepted solution]

Hi

This is clean

cat filein|while read line
do
for i in $(echo HDR POL OBJ)
do
echo |grep ^$i >> fileout 2>/dev/null
done
done


filein = old fileout=new


Steve Steel

[Declan Heerey]

Thanks for that guys - both methods worked, i'm spoiled for choice as to which to use! I'll compare both for speed on bigger files!!!

Thanks again