It is very similar to running gpg-agent in server mode; but here we connect to a running instance.

The following options may be used:

-v

--verbose

Output additional information while running.

-q

--quiet

Try to be as quiet as possible.

--homedir dir

Set the name of the home directory to dir. If this option is not used, the home directory defaults to oq~/.gnupgcq. It is only recognized when given on the command line. It also overrides any home directory stated through the environment variable oqGNUPGHOMEcq or (on W32 systems) by means of the Registry entry HKCU\Software\GNU\GnuPG:HomeDir.

-S

--raw-socket name

Connect to socket name assuming this is an Assuan style server. Do not run any special initializations or environment checks. This may be used to directly connect to any Assuan style socket server.

-E

--exec

Take the rest of the command line as a program and it's arguments and execute it as an assuan server. Here is how you would run gpgsm:

gpg-connect-agent --exec gpgsm --server

Note that you may not use options on the command line in this case.

--no-ext-connect

When using -S or --exec, gpg-connect-agent connects to the assuan server in extended mode to allow descriptor passing. This option makes it use the old mode.

--run file

Run the commands from file at startup and then continue with the regular input method. Note, that commands given on the command line are executed after this file.

-s

--subst

Run the command /subst at startup.

--hex

Print data lines in a hex format and the ASCII representation of non-control characters.

--decode

Decode data lines. That is to remove percent escapes but make sure that a new line always starts with a D and a space.

While reading Assuan commands, gpg-agent also allows a few special commands to control its operation. These control commands all start with a slash (/).

/echo args

Just print args.

/let name value

Set the variable name to value. Variables are only substituted on the input if the /subst has been used. Variables are referenced by prefixing the name with a dollar sign and optionally include the name in curly braces. The rules for a valid name are identically to those of the standard bourne shell. This is not yet enforced but may be in the future. When used with curly braces no leading or trailing white space is allowed.

If a variable is not found, it is searched in the environment and if found copied to the table of variables.

Variable functions are available: The name of the function must be followed by at least one space and the at least one argument. The following functions are available:

get

Return a value described by the argument. Available arguments are:

cwd

The current working directory.

homedir

The gnupg homedir.

sysconfdir

GnuPG's system configuration directory.

bindir

GnuPG's binary directory.

libdir

GnuPG's library directory.

libexecdir

GnuPG's library directory for executable files.

datadir

GnuPG's data directory.

serverpid

The PID of the current server. Command /serverpid must have been given to return a useful value.

unescape args

Remove C-style escapes from args. Note that \0 and \x00 terminate the returned string implicitly. The string to be converted are the entire arguments right behind the delimiting space of the function name.

unpercent args

unpercent+ args

Remove percent style escaping from args. Note that %00 terminates the string implicitly. The string to be converted are the entire arguments right behind the delimiting space of the function name. unpercent+ also maps plus signs to a spaces.

percent args

percent+ args

Escape the args using percent style escaping. Tabs, formfeeds, linefeeds, carriage returns and colons are escaped. percent+ also maps spaces to plus signs.

errcode arg

errsource arg

errstring arg

Assume arg is an integer and evaluate it using strtol. Return the gpg-error error code, error source or a formatted string with the error code and error source.

+

-

*

/

%

Evaluate all arguments as long integers using strtol and apply this operator. A division by zero yields an empty string.

!

|

&

Evaluate all arguments as long integers using strtol and apply the logical oeprators NOT, OR or AND. The NOT operator works on the last argument only.

/definq name var

Use content of the variable var for inquiries with name. name may be an asterisk (*) to match any inquiry.

/definqfile name file

Use content of file for inquiries with name. name may be an asterisk (*) to match any inquiry.

/definqprog name prog

Run prog for inquiries matching name and pass the entire line to it as command line arguments.

/datafile name

Write all data lines from the server to the file name. The file is opened for writing and created if it does not exists. An existing file is first truncated to 0. The data written to the file fully decoded. Using a single dash for name writes to stdout. The file is kept open until a new file is set using this command or this command is used without an argument.

/showdef

Print all definitions

/cleardef

Delete all definitions

/sendfd file mode

Open file in mode (which needs to be a valid fopen mode string) and send the file descriptor to the server. This is usually followed by a command like INPUT FD to set the input source for other commands.

/recvfd

Not yet implemented.

/open var file [mode]

Open file and assign the file descriptor to var. Warning: This command is experimental and might change in future versions.

/close fd

Close the file descriptor fd. Warning: This command is experimental and might change in future versions.

/showopen

Show a list of open files.

/serverpid

Send the Assuan command GETINFO pid to the server and store the returned PID for internal purposes.

/sleep

Sleep for a second.

/hex

/nohex

Same as the command line option --hex.

/decode

/nodecode

Same as the command line option --decode.

/subst

/nosubst

Enable and disable variable substitution. It defaults to disabled unless the command line option --subst has been used. If /subst as been enabled once, leading whitespace is removed from input lines which makes scripts easier to read.

/while condition

/end

These commands provide a way for executing loops. All lines between the while and the corresponding end are executed as long as the evaluation of condition yields a non-zero value. The evaluation is done by passing condition to the strtol function. Example:

/subst
/let i 3
/while $i
/echo loop couter is $i
/let i ${- $i 1}
/end

/run file

Run commands from file.

/bye

Terminate the connection and the program

/help

Print a list of available control commands.

The full documentation for this tool is maintained as a Texinfo manual. If GnuPG and the info program are properly installed at your site, the command

info gnupg

should give you access to the complete manual including a menu structure and an index.