Document pseudo-commands.

doc/apps/openssl.pod

@@ -12,6 +12,10 @@ I<command>
 [ I<command_opts> ]
 [ I<command_args> ]
 
+B<openssl> [ B<list-standard-commands> | B<list-message-digest-commands> | B<list-cipher-commands> ]
+
+B<openssl> B<no->I<XXX> [ I<arbitrary options> ]
+
 =head1 DESCRIPTION
 
 OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL
@@ -35,6 +39,22 @@ The B<openssl> program provides a rich variety of commands (I<command> in the
 SYNOPSIS above), each of which often has a wealth of options and arguments
 (I<command_opts> and I<command_args> in the SYNOPSIS).
 
+The pseudo-commands B<list-standard-commands>, B<list-message-digest-commands>,
+and B<list-cipher-commands> output a list (one entry per line) of the names
+of all standard commands, message digest commands, or cipher commands,
+respectively, that are available in the present B<openssl> utility.
+
+The pseudo-command B<no->I<XXX> tests whether a command of the
+specified name is available.  If no command named I<XXX> exists, it
+returns 0 (success) and prints B<no->I<XXX>; otherwise it returns 1
+and prints I<XXX>.  In both cases, the output goes to B<stdout> and
+nothing is printed to B<stderr>.  Additional command line arguments
+are always ignored.  Since for each cipher there is a command of the
+same name, this provides an easy way for shell scripts to test for the
+availability of ciphers in the B<openssl> program.  (B<no->I<XXX> is
+not able to detect pseudo-commands such as B<quit>,
+B<list->I<...>B<-commands>, or B<no->I<XXX> itself.)
+
 =head2 STANDARD COMMANDS
 
 =over 10
@@ -296,7 +316,10 @@ L<crypto(3)|crypto(3)>, L<ssl(3)|ssl(3)>
 
 =head1 HISTORY
 
-The openssl(1) document appeared in OpenSSL 0.9.2
+The openssl(1) document appeared in OpenSSL 0.9.2.
+The B<list->I<XXX>B<-commands> pseudo-commands were added in OpenSSL 0.9.3;
+the B<no->I<XXX> pseudo-commands were added in OpenSSL 0.9.5a.
+For notes on the availability of other commands, see their individual
+manual pages.
 
 =cut
-