#!/bin/sh

# Parsing CSV files with sed

# we convert csv files into a simplified interchange format:
# text characters separated by tabs! we escape tabs, newlines, and backslashes
# into \t, \n, and \\.

# these functions process on standard input and standard output.
# we allow CR LFs in input but we don't output them by default.

# see csv.sh for an unminified version.

# made by Natalia Posting in 2023

from_csv () {
	LC_ALL=C sed -n 's/'"$(printf "\r")"'$//;s/\\/\\\\/g;s/'"$(printf "\t")"'/\\t/g;H;x;h;s/^\n//;s/\n/\\n/g;s/,/,,/g;s/$/,/;s/^/,/;s/,\([^",]*\("[^"]*\(""[^"]*\)*"[^",]*\)*\),/\1'"$(printf "\t")"'/g;/,$/d;s/.$//;s/,,/,/g;s/"\([^"]*\(""[^"]*\)*\)"/\1/g;s/""/"/g;p;s/.*//;h'
}


to_csv () {
	LC_ALL=C sed 's/"/""/g;s/'"$(printf "\t")"'/","/g;s/^/"/;s/$/"/;s/\\\\/& /g;s/\\n/\n/g;s/\\t/'"$(printf "\t")"'/g;s/\\\\ /\\/g;'
}