Mailutils info
The mailutils info command displays information about GNU Mailutils compile-time configuration. In normal form its output lists a single configuration flag per line, e.g.:
$ mailutils info VERSION=2.99.99 SYSCONFDIR=/etc MAILSPOOLDIR=/var/mail/ SCHEME=mbox LOG_FACILITY=mail IPV6 USE_LIBPAM HAVE_LIBLTDL WITH_GDBM WITH_GNUTLS WITH_GSASL ...
A configuration flag can consist either of a single word, indicating that a particular capability has been enabled at compile time, or of a keyword/value pair delimited by an equal sign, which indicates a particular value used by default for that feature. For example, IPV6 means that Mailutils was compiled with support for IPv6, whereas SYSCONFDIR=/etc means that the default place for configuration files is in /etc directory.
Such short output is convenient for using mailutils info in scripts to decide whether it is possible to use a given feature. To assist human users, the --verbose (-v) option is provided. It prints a short description next to each flag:
$ mailutils info --verbose VERSION=2.99.98 - Version of this package SYSCONFDIR=/etc - System configuration directory MAILSPOOLDIR=/var/mail/ - Default mail spool directory SCHEME=mbox - Default mailbox type LOG_FACILITY=mail - Default syslog facility IPV6 - IPv6 support USE_LIBPAM - PAM support HAVE_LIBLTDL - a portable `dlopen' wrapper library WITH_GDBM - GNU DBM WITH_GNUTLS - TLS support using GNU TLS WITH_GSASL - SASL support using GNU SASL ...