The ap program treats each argument as one or more addresses, and prints those addresses out in the official 822-format. Hence, it is usually best to enclose each argument in double-quotes for the shell.
To override the output format used by ap, the -format string or -format file switches are used. This permits individual fields of the address to be extracted with ease. The string is simply a format string, and the file is simply a format file. See mh-format(5) for the details.
In addition to the standard escapes, ap also recognizes the following additional escape:
Escape Returns Description error string A diagnostic if the parse failed
If the -normalize switch is given, ap will try to track down the official hostname of the address.
Here is the default format string used by ap:
which says that if an error was detected, print the error, a `:', and the address in error. Otherwise, output the 822-proper format of the address.
^$HOME/.mh_profile~^The user profile ^/etc/nmh/mts.conf~^nmh mts configuration file
`-format' defaults as described above `-normalize' `-width' defaults to the width of the terminal