How to parse a CSV file in Bash?

问题:

I'm working on a long Bash script. I want to read cells from a CSV file into Bash variables. I can parse lines and the first column, but not any other column. Here's my code so far:

  cat myfile.csv|while read line
  do
    read -d, col1 col2 < <(echo $line)
    echo "I got:$col1|$col2"
  done

It's only printing the first column. As an additional test, I tried the following:

read -d, x y < <(echo a,b,)

And $y is empty. So I tried:

read x y < <(echo a b)

And $y is b. Why?

回答1:

You need to use IFS instead of -d:

while IFS=, read -r col1 col2
do
    echo "I got:$col1|$col2"
done < myfile.csv

Note that for general purpose CSV parsing you should use a specialized tool which can handle quoted fields with internal commas, among other issues that Bash can't handle by itself. Examples of such tools are cvstool and csvkit.

回答2:

From the man page:

-d delim The first character of delim is used to terminate the input line, rather than newline.

You are using -d, which will terminate the input line on the comma. It will not read the rest of the line. That's why $y is empty.