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echo " a" | while read; do echo "$REPLY"; done
will output ".....a" which contains leading white space. However,
echo " a" | while read line; do echo "$line"; done
will output "a" with leading white space skipped (OK, because word splitting).
It seems the REPLY variable has the same effect of IFS set to null:
echo " a" | while IFS= read line; do echo "$line"; done
From the bash manual, I can't find the reason. Do you have any ideas? Thanks.
From read man page:
Read one line from the standard input, (or from a file) and assign the word(s) to variable name(s).
If no names are supplied, the line read is assigned to the variable REPLY.
So, $REPLY is always the whole line, while the assigned variables are always words. It would not work otherwise e.g. if you have multiple words, what would $REPLY be?
