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astTest - Test if an Object attribute value is set   

Description:
This function returns a boolean result (0 or 1) to indicate whether a value has been explicitly set for one of an Object's attributes.

Synopsis:
int astTest( AstObject *this, const char *attrib )

Parameters:
this
Pointer to the Object.
attrib
Pointer to a null-terminated character string containing the name of the attribute to be tested.

Class Applicability:
Object
This function applies to all Objects.

Returned Value:
astTest()
One if a value has previously been explicitly set for the attribute (and hasn't been cleared), otherwise zero.

Notes:
  • Attribute names are not case sensitive and may be surrounded by white space.
  • A value of zero will be returned if this function is invoked with the AST error status set, or if it should fail for any reason.
  • A value of zero will also be returned if this function is used to test a read-only attribute, although no error will result.



next up previous
Next: astText - Draw a text string for a Plot
Up: AST Function Descriptions
Previous: astStatus - Obtain the current AST error status value

AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
30th April 2003
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2003 Central Laboratory of the Research Councils