Replacing first column csv with variable

Question

I can't believe I couldn't find my question anywhere else in the bash/linux community. I simply want to replace the first column of my csv file with a variable...

0,8,9,10
0,8,9,10
0,8,9,10
0,8,9,10
0,8,9,10
0,8,9,10


2/24/14,8,9,10
2/24/14,8,9,10
2/24/14,8,9,10
2/24/14,8,9,10
2/24/14,8,9,10
2/24/14,8,9,10

I simply just want to replace the first column with $date, but all the awk commands don't allow a variable as a the replacement.

Answer 1

This should work:

awk -v dt="$date" 'BEGIN{FS=OFS=","}{$1=dt}1' inputFile

Explaination:

• Use -v option to set an awk variable and assign it your shell variable.
• Set the Input Field Separator and Output Field Separator to , (since it is a csv)
• Set the value of $1 to your awk variable.
• 1 is to print the line with modified $1.