HEADER(1)HEADER(1)NAMEheader - extract fields from mail headerSYNOPSISheader [-c] [-n] [-v] [-f fieldname] ...
The header program reads a mail header on its standard input. Any text
that follows the header is ignored. It then prints all, part, or none
of the header to its standard output, depending on its command line
OPTIONS-c Match field names only if their cases match. Normally, mail
header field names are case-insensitive.
-n Prefix displayed header fields with their names. The resulting
output is itself a valid header (albeit possibly shorter). By
default, only field values are displayed.
-v Print only the fields that are not listed in -f options.
Display (or delete, if -v) header fields with the given name.
Please mail enhancements, enhancement requests, trouble reports, etc.
to <email@example.com>. See also the Debian GNU/Linux bug tracking system