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    +1 Thanks for some useful insights of the different treatments on space/tab vs "others" in IFS in bash... I knew they were treated differently, but this explanation simplifies it all a lot. (And the insight between bash (and other posix shells) and the regular sh differences is usefull too to write portable scripts!) Commented Jun 12, 2015 at 12:34
  • At least for bash-4.4.19, while read -r; do echo "'$REPLY'"; done works as while IFS= read -r line; do echo "'$line'"; done. Commented May 28, 2018 at 14:25
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    This: "...that erroneous notion that read is the command to read a line..." leads me to think, that if using read to read a line is erroneous, there must be something else. What could that non-erroneous notion be? Or is that first statement technically correct, but in truth the non-erroneous notion is: "read is the command to read words from a line. Because it's so powerful, you can use it to read lines from a file by doing: IFS= read -r line" Commented Jul 16, 2018 at 15:24
  • If you write IFS=$'\n', is that the same as IFS= but with the trailing \n stripped off the end of each line? Commented Oct 6, 2023 at 17:05
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    @shadowtalker, though you do sometimes see IFS=$'\n' read -r line being used here and there, it is pointless as read -r line reads the input up to a newline, but the newline is not included in what is read, so read could never split on newline on the result. So it's exactly the same as IFS= read -r line. In any case, it's better than forgetting the IFS=. It could make sense if using a different delimiter as supported with-d in some read implementations. IFS=$'\n' read -rd '' record would read a NUL delimited record and remove leading and trailing newlines in it. Commented Oct 6, 2023 at 18:25