bash method to remove last 4 columns from csv file

cat data.csv | rev | cut -d, -f-5 | rev

rev reverses the lines, so it doesn't matter if all the rows have the same number of columns, it will always remove the last 4. This only works if the last 4 columns don't contain any commas themselves.

You can use cut for this if you know the number of columns. For example, if your file has 9 columns, and comma is your delimiter:

cut -d',' -f -5

However, this assumes the data in your csv file does not contain any commas. cut will interpret commas inside of quotes as delimiters also.

Cut can do this if all lines have the same number of fields or awk if you don't.

cut -d, -f1-6 # assuming 10 fields

Will print out the first 6 fields if you want to control the output seperater use --output-delimiter=string

awk -F , -v OFS=, '{ for (i=1;i<=NF-4;i++){ printf $i, }; printf "\n"}'

Loops over fields up to th number of fields -4 and prints them out.