doc: Document decryption support in pspp-convert.

Reported by tylar <murray.tylar@gmail.com>.

diff --git a/doc/pspp-convert.texi b/doc/pspp-convert.texi
index 350fc9b0cdfc90c5ec42c072e765ff3b7727c76f..838f81167cf6b6be1850d4f1d6daf278ca90b16d 100644 (file)
--- a/doc/pspp-convert.texi
+++ b/doc/pspp-convert.texi
@@ -40,12 +40,18 @@ SPSS system file.
 SPSS portable file.
 @end table
 
+As a special case of format conversion, @command{pspp-convert} can
+decrypt an encrypted SPSS system file.  Specify the encrypted file as
+@var{input}.  The output will be the equivalent plaintext SPSS system
+file.  You will be prompted for the password (or use @option{-p},
+documented below).
+
 Use @code{-O @var{extension}} to override the inferred format or to
 specify the format for unrecognized extensions.
 
 The following options are accepted:
 
-@table @code
+@table @option
 @item -O @var{format}
 @itemx --output-format=@var{format}
 Specifies the desired output format.  @var{format} must be one of the
@@ -64,6 +70,15 @@ Overrides the encoding in which character strings in @var{input} are
 interpreted.  This option is necessary because old SPSS system files,
 and SPSS/PC+ system files, do not self-identify their encoding.
 
+@item -p @var{password}
+@item --password=@var{password}
+Specifies the password to use to decrypt an encrypted SPSS system
+file.  If this option is not specified, @command{pspp-convert} will
+prompt interactively for the password as necessary.
+
+Be aware that command-line options, including passwords, may be
+visible to other users on multiuser systems.
+
 @item -h
 @itemx --help
 Prints a usage message on stdout and exits.