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3.2 Client requests

The server waits for client requests after sending an Okay or Error. The client should not issue a request in other cases.

command <parameters>

command is a one word string without preceding white space. Parameters are command specific, CR, LF and the percent signs should be percent escaped as described above. To send a backslash as the last character it should also be percent escaped. Percent escaping is allowed anywhere in the parameters but not in the command. The line ends with a CR, LF pair or just a LF.

Not yet implemented feature: If there is a need for a parameter list longer than the line length limit (1000 characters including command and CR, LF), the last character of the line (right before the CR/LF or LF) must be a unescaped (i.e., literal) backslash. The following line is then expected to be a continuation of the line with the backslash replaced by a blank and the line ending removed.

D <raw data>

Sends raw data to the server. There must be exactly one space after the ’D’. The values for ’%’, CR and LF must be percent escaped. These are encoded as %25, %0D and %0A, respectively. Only uppercase letters should be used in the hexadecimal representation. Other characters may be percent escaped for easier debugging. All Data lines are considered one data stream up to the OK or ERR response. Status and Inquiry Responses may be mixed with the Data lines.


Lines beginning with a # or empty lines are ignored. This is useful to comment test scripts.

Although the commands are application specific, some of them are used by all protocols and partly supported by the Assuan library:


Close the connection. The server will respond with OK.


Reset the connection but not any existing authentication. The server should release all resources associated with the connection.


Used by a client to mark the end of raw data. The server may send END to indicate a partial end of data.


Lists all commands that the server understands as comment lines on the status channel.


Reserved for future extensions.


Set options for the connection. The syntax of such a line is

  OPTION name [ [=] value ]

Leading and trailing spaces around name and value are allowed but should be ignored. For compatibility reasons, name may be prefixed with two dashes. The use of the equal sign is optional but suggested if value is given.


This command is reserved for future extensions.


This command is reserved for future extensions. Not yet specified as we don’t implement it in the first phase. See Werner’s mail to gpa-dev on 2001-10-25 about the rationale for measurements against local attacks.


No operation. Returns OK without any action.

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