px_retrieve_record(3) [debian man page]

PX_RETRIEVE_RECORD(3)					     Library Functions Manual					     PX_RETRIEVE_RECORD(3)

NAME

       PX_retrieve_record -- Returns record in Paradox file

SYNOPSIS

       #include <paradox.h>

       pxval_t ** PX_retrieve_record(pxdoc_t *pxdoc, int recno)

DESCRIPTION

       Returns the record with the given number in a Paradox file. The first record has number 0, the last one has number_of_records-1.

       If you are accessing several records, do it in ascending order, because this is the most efficient way.

       The return value is an array of field values. Each value is stored in a structure like the following:

       typedef struct px_val pxval_t;
       struct px_val {
       char isnull;
       int type;
       union {
       long lval;
       double dval;
       struct {
       char *val;
       int len;
       } str;
       } value;
       };

       The  element  isnull  is  set  to  1 if the value is NULL otherwise it is set to 0. type 	       is the type of the paradox field as
       defined in paradox.h.  A field value can be either a long int, a double or a string, depending on the paradox field type. The paradox field
       types  pxfShort,  pxfLong,  pxfDate,  pxfTime,  pxfLogical,  and  pxfAutoInc are returned as long int values.  pxfTimestamp, pxfNumber, and
       pxfCurrency are returned as double values and all remaining paradox field types are stored as strings with the length in value.len. You can
       rely on strings being Null terminated. Blobs are stored as string but are not guarented to be Null terminated.

       The  paradox  field  types  pxfTimestamp,  pxfTime,  an	pxfDate  use an uncommon format which can be converted into a string with PX_time-
       stamp2string(3), PX_time2string(3), and PX_date2string(3).

RETURN VALUE

       Returns a pointer on success and NULL on failure.

SEE ALSO

       PX_update_record(3), PX_timestamp2string(3), PX_time2string(3), PX_date2string(3)

AUTHOR

       This manual page was written by Uwe Steinmann uwe@steinmann.cx.

															     PX_RETRIEVE_RECORD(3)

EGD_CHANNEL_INFO(3)					       EEGDEV library manual					       EGD_CHANNEL_INFO(3)

NAME

       egd_channel_info - Get various information about a particular channel

SYNOPSIS

       #include <eegdev.h>

       int egd_channel_info(const struct eegdev* dev, int stype,
			     unsigned int index, int fieldtype, ...);

DESCRIPTION

       egd_channel_info()  provides  different	type  of  information  about the channel at the index index of the group specified by stype of the
       device referenced by dev. As described for egd_acq_setup(3), stype specifies the type of channel. It must one of  the  values  returned	by
       egd_sensor_type(3).

       The  information  returned by the function is defined by the variable list of argument. This list is composed of successive couple grouping
       one field type identifier specifying the feature to be get and a pointer to a value whose type depends on the previous field type. The list
       must finish by EGD_END.

       The field identifers can be the following (The expected corresponding pointer type is provided in parenthesis):

       EGD_LABEL (char*)
	      Name of the channel. The pointed array should be long enough to hold 32 characters (including the null termination character).

       EGD_ISINT (int*)
	      Indicates whether the data provided by the channel are integer or floating point. (zero indicates floating point, non-zero indicates
	      integer).

       EGD_MM_I (int32_t*)
	      Returns in an array of 2 int32_t the minimal and maximal values that the channel can deliver (If the channel deliver floating  point
	      data, these values can be underestimated due to overflow)

       EGD_MM_F (float*)
	      Returns  in  an  array  of 2 float values the minimal and maximal values that the channel can deliver (If the channel deliver double
	      floating point data, these values can be underestimated due to overflow)

       EGD_MM_D (double*)
	      Returns in an array of 2 double values the minimal and maximal values that the channel can deliver.

       EGD_UNIT (char*)
	      Unit in which the channel data is expressed. The pointed array should be long enough to hold 16 characters (including the null  ter-
	      mination character).

       EGD_TRANSDUCTER (char*)
	      Transducter type of the sensor. The pointed array should be long enough to hold 128 characters (including the null termination char-
	      acter).

       EGD_PREFILTERING (char*)
	      Information about the filters already applied on data. The pointed array should be long enough to hold 128 characters (including the
	      null termination character).

RETURN VALUE

       The function returns 0 in case of succes. Otherwise, -1 is returned and errno is set accordingly.

ERRORS

       egd_channel_info() will fail if:

       EINVAL dev  is NULL, stype is an invalid sensor type, index is bigger than the maximal number of channel in the group, any field identifier
	      is unknown or any pointer used is NULL.

THREAD SAFETY

       egd_channel_info() is thread-safe.

SEE ALSO

       egd_acq_setup(3), egd_sensor_type(3)

EPFL
								       2010						       EGD_CHANNEL_INFO(3)