10.7.2 Control commands

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 operators 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 counter 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.

/history --clear

Clear the command history.

/bye

Terminate the connection and the program.

/help

Print a list of available control commands.