Communicate with a running agent
gpg-connect-agent [options][commands]
The gpg-connect-agent is a utility to communicate with a running gpg-agent. It is useful to check out the commands gpg-agent provides using the Assuan interface. It might also be useful for scripting simple applications. Input is expected at stdin and out put gets printed to stdout.
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~/.gnupg\(cq. It is only recognized when given on the command line. It also overrides any home directory stated through the environment variable \(oqGNUPGHOME\(cq or (on W32 systems) by means of the Registry entry HKCU\Software\GNU\GnuPG:HomeDir.
--agent-program file
Specify the agent program to be started if none is running.
-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 or is the string true or yes. 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
/if condition
/end
These commands provide a way for conditional execution. All lines between the if and the corresponding end are executed only if the evaluation of condition yields a non-zero value or is the string true or yes. The evaluation is done by passing condition to the strtol function.
/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.