parseHeaderSection method
parse a section from all of header.
parse and get section data in header
.
header
is all of the header string.
this function searches a section of section
in header
, then parses and returns the found data.
section's format is
Implementation
String? parseHeaderSection(String header, String section) {
RegExpMatch? valueMatch =
RegExp('^$section=(.*?)\$', dotAll: true, multiLine: true)
.firstMatch(header);
return valueMatch?.group(1);
}