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ds_get()

Retrieve a data server variable

Synopsis:

#include <ds.h>

int ds_get( ds_t dsdes,
            const char* variable_name,
            const char* variable_data,
            size_t data_len );

Arguments:

dsdes: A data server descriptor returned by ds_register().
variable_name: The name of the data server variable that you want to get.
variable_data: A buffer where the function can store the data associated with the variable.
data_len: The size of the buffer, in bytes.

Library:

libds

Use the -l ds option to qcc to link against this library.

Description:

The ds_get() function retrieves the data corresponding to variable_name from the data server dsdes, and places it in the buffer pointed to by variable_data.

Returns:

The amount of data written to the buffer variable_data, or -1 if an error occurs (errno is set).

Errors:

EBADF: Invalid file descriptor dsdes.
EMSGSIZE: The buffer isn't big enough for the data.
ESRCH: The variable doesn't exist in the data server.

Classification:

QNX Neutrino

Safety:
Cancellation point	Yes
Interrupt handler	No
Signal handler	Yes
Thread	Yes