How to read stdin as well as files?

[Peng Yu]

The following example shows that when files are specified, stdin will
not be read.

What is the best way to first read stdin then read the files (knowing
where the data is from)? Thanks.

$ seq 3 | awk -e '{ print FILENAME, $0 }' <(printf '%s\n' {a..c})
<(printf '%s\n' {A..B})
/dev/fd/63 a
/dev/fd/63 b
/dev/fd/63 c
/dev/fd/62 A
/dev/fd/62 B

-- 
Regards,
Peng