Re: Bash Reference Mamual

[Lawrence Velázquez]

> On Oct 17, 2020, at 7:35 PM, Eduardo Bustamante <dualbus@gmail.com> wrote:
> 
> <(cat file) and $(cat file) are not equivalent constructs. The former will
> expand to a file name (e.g. "/dev/fd/63"), whereas the latter will expand
> to the contents of the file.

If you want terms you can look up, $(cat file) and $(< file) are
*command substitutions*, while <(cat file) is a *process substitution*.

$ printf 'FILE CONTENTS' >tmp
$ printf '|%s|\n' "$(cat tmp)"
|FILE CONTENTS|
$ printf '|%s|\n' "$(< tmp)"
|FILE CONTENTS|
$ printf '|%s|\n' "<(cat tmp)"
|<(cat tmp)|
$ printf '|%s|\n' <(cat tmp)
|/dev/fd/63|


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vq