Add number of line with awk

Question

i would to know how can i edit my csv file to add first column with name 'linenumber' and iterate through each line and insert the number of the line in this column ?

Something like that

TEST TEST2 TEST3
valu value value

To that

linenumber TEST TEST2 TEST3
1          valu value value

Thanks in advance

Stoufiler

Answer 1

Following awk should help you on same.

awk 'FNR==1{print "linenumber",$0;next} {print FNR-1,$0}'   Input_file

In case you need to edit the Input_file itself then following may help you.

awk 'FNR==1{print "linenumber",$0;next} {print FNR-1,$0}'  OFS=","  Input_file > temp_file && mv temp_file  Input_file

Answer 2

i found the answer, it's that

awk 'FNR==1{print "linenumber,"$0;next} {print FNR-1,$0}' OFS="," input.csv > output.csv

thanks for all