Here is a dummy CSV file with 3 rows. The actual file has 7 million rows.
testdates.csv:
y_m_d
1997-01-01
1985-06-09
1943-07-14
The date tool can usually be formatted as such , to get the 'day' :
date -d "25 JUN 2011" +%A
=> output: Saturday
Query: How to provide an entire column as input for the date +%A transformation?
The resulting output should be appended to the end of the input file.
Intended output:
y_m_d, Day
1997-01-01, Thursday
1985-06-09, …