tt_message_receive(3)

NAME

tt_message_receive − receive a message

SYNOPSIS

#include <Tt/tt_c.h>
Tt_message tt_message_receive(void);

DESCRIPTION

The tt_message_receive() function returns a handle for the next message queued to be delivered to the process and also runs any message or pattern callbacks applicable to the queued message.

If the return value of tt_message_status(3) for this message is TT_WRN_START_MESSAGE, the ToolTalk service started the process to deliver the queued message; the process must reply to this message. If the return value of tt_message_receive() is zero, no message is available.

RETURN VALUE

Upon successful completion, the tt_message_receive() function returns the handle for the message object. The application can use tt_ptr_error(3) to extract one of the following Tt_status values from the returned handle:

TT_OK
The operation completed successfully.

TT_ERR_NOMP
The ttsession(1) process is not running and the ToolTalk service cannot restart it.

TT_ERR_STATE
The Tt_message is in a Tt_state that is invalid for the attempted operation.

APPLICATION USAGE

A zero value can occur if a message or pattern callback processes the message. It can also occur if the interval is too long between the time the file descriptor became active and the tt_message_receive() call was made. In the latter case, the ToolTalk service will time out and offer the message to another process.

The application should check the tt_message_uid(3) and tt_message_gid(3) against the User ID and Group ID of the application receiving the messsage. If the UID and/or GID of the application do not match that of the message then the receiving application should consider failing the message with TT_DESKTOP_EACCES.

The application should use tt_free(3) to free any data stored in the address returned by the ToolTalk API.

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