1 files changed, 63 insertions, 0 deletions
diff --git a/pkg/tbtables/selector/whatfile.x b/pkg/tbtables/selector/whatfile.x
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+++ b/pkg/tbtables/selector/whatfile.x
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+include <imhdr.h>
+include "whatfile.h"
+
+# WHATFILE -- Return integer code indicating type of image
+#
+# B. Simon,                Original.
+# Phil Hodge, 22-Feb-2002  Use tbtacc instead of tbtopn to test for a table.
+# Phil Hodge, 19-Sep-2002  Simplify is_image(), just use tbtacc or imaccess.
+
+
+int procedure whatfile (file)
+
+char	file[ARB]	# i: file name
+#--
+int	flag
+
+int	is_image()
+
+begin
+	# This function exists mostly for backwards compatibility. 
+	# The recommended function to use is is_image, as it does
+	# not need special macros
+
+	switch (is_image(file)) {
+	case ERR:
+	    flag = IS_UNKNOWN
+	case NO:
+	    flag = IS_TABLE
+	case YES:
+	    flag = IS_IMAGE
+	}
+
+	return (flag)
+end
+
+# IS_IMAGE -- Return YES if file is image, NO if table, and ERR if can't decide
+#
+# Note that a function value of NO does not just mean that the file is not
+# an image, it means that it _is_ a table.  Note also that while a FITS
+# primary header or IMAGE extension can be opened as a table (for access
+# to the header), tbtacc will return NO for such an extension.
+#
+# The 'file' argument to this function should be the complete image or
+# table name, i.e. including FITS extension number or name, or STF group
+# number.
+
+int procedure is_image (file)
+
+char	file[ARB]	# i: file name
+#--
+int	image
+int	imaccess(), tbtacc()
+
+begin
+	if (tbtacc (file) == YES)
+	    image = NO
+	else if (imaccess (file, READ_ONLY) == YES)
+	    image = YES
+	else
+	    image = ERR
+
+	return image
+end