NAME¶
egd_get_cap - Query various information about the device capabilities
SYNOPSIS¶
#include <eegdev.h>
int egd_get_cap(const struct eegdev* dev, int
cap, void* val);
DESCRIPTION¶
egd_get_cap() returns the information about the capability specified by
cap of the recording device referenced by
dev by the mean of the
pointer
val.
The type of pointer passed through
val is dependent on the requested
capability
cap which can be one the following (The expected type
pointed by
val is provided in parenthesis):
- EGD_CAP_FS (int)
- Sampling frequency that is currently set. The same value is returned by
the function.
- EGD_CAP_TYPELIST (const int*)
- Array of sensor types sampled by the device terminated by -1. These values
became valid as argument for egd_sensor_name(3) when opening the
device dev if they were not yet before. The number of elements in
the array (excluding the -1 element) is provided by the return value of
the function.
- EGD_CAP_DEVTYPE (const char*)
- Null terminated string describing the type of the recording device
(Manufacturer and model if dev refers to actual hardware). The
length of string (excluding the null character) is provided by the return
value of the function.
- EGD_DEVID (const char*)
- Null-terminated string describing the model of the recording device (or an
unique identifier of the resource). The length of string (excluding the
null character) is provided by the return value of the function.
RETURN VALUE¶
In case of success, the function returns a positive value depending on the
requested capability. Otherwise, -1 is returned and
errno is set
accordingly.
ERRORS¶
egd_get_cap() will fail if:
- EINVAL
- dev is NULL, cap is not valid value or val is NULL
while cap is not EGD_CAP_FS.
SEE ALSO¶
egd_sensor_name(3)