cat file | … vs … <file

Question

Is there a case of ... or context where cat file | ... behaves differently than ... ?

Answer 1

Pipes cause a subshell to be invoked for the command on the right. This interferes with environment variables.

cat foo | while read line
do
  ...
done
echo "$line"

versus

while read line
do
  ...
done < foo
echo "$line"