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gsdGet0<t> - Get a scalar value from a GSD file

Description:
This routine returns the value of a scalar GSD item. The item must be specified by the file desciptor, item descriptor array, data array and item number.

<t> <type> Fortran GSD
b char byte byte
l char logical*1 logical
w short integer*2 word
i int integer*4 integer
r float real*4 real
d double real*8 double
c char[17] character*16 char

This routine will convert between numeric types (all but GSD type char). That is to say, the calling routine can request, say, an integer value by calling gsdGet0i, even if the item in the GSD file has a different numeric type, say real. C casting rules are applied, which may differ from Fortran truncation rules. No test for conversion errors is performed.


Invocation:
int gsdGet0{blwirdc}( void *file_dsc, void *item_dsc, char *data_ptr, int itemno, <type> *value );

Arguments:

void *file_dsc (Given)
The GSD file descriptor.
void *item_dsc (Given)
The array of GSD item descriptors related to the GSD file.
char *data_ptr (Given)
The buffer with all the data from the GSD file.
int itemno (Given)
The number of the item in the GSD file.
<type> *value (Returned)
The data value. For gsdGet0c value should be declared with length 17 at least. The returned string is null-terminated in value[16].

Returned Value:

int gsdGet0<t>();
Status.

1:
Failure to read the item value.

2:
Numbered item cannot be found.

3:
Item is not scalar.

0:
Otherwise.


Prototype
available via #include "gsd.h"
Copyright
Copyright (C) 1986-1999 Particle Physics and Astronomy Research Council. All Rights Reserved.


next up previous 193
Next: gsdGet1<t> - Get an array from a GSD file
Up: Routine Descriptions
Previous: gsdFind - Find GSD item by name

The Global Section Datafile (GSD) access library
Starlink User Note 229
Tim Jenness, Remo Tilanus,
Horst Meyerdierks, Jon Fairclough
16 December 1999
E-mail:ussc@star.rl.ac.uk