On Tue, Feb 5, 2013 at 6:39 PM, Tiwo W. <tiwoc...@gmail.com> wrote: > I have seen "read -d '' var" to read multi-line heredocs into > shell variables. An empty argument to -d seemed to mean "read > up to the end of input". And this is what it does. > > In addition to all of the "don't use set -e" answers you've gotten (which i agree with wholeheartedly), I have this to add:
read -rd '' is synonymous to read -d $'\0'. It doesn't actually mean "read until the end of input", but rather "read until a NUL byte is encountered". You see this usage a lot as well when reading NUL-delimited data, say filenames from find. For example: while IFS= read -rd '' file; do some_command "$file" done < <(find . -type f -print0) So what's actually happening with your here document usage case is that read is looking for a NUL byte, but never finds one, so it stops reading when EOF is encountered. As Greg mentioned, this then casuse read to exit > 0. This is a perfectly acceptable usage, but now you know why that happens. And to reiterate, STOP USING set -e!
