1 files changed, 67 insertions, 0 deletions
diff --git a/fitsy/headdata.c b/fitsy/headdata.c
new file mode 100644
index 0000000..748fbea
--- /dev/null
+++ b/fitsy/headdata.c
@@ -0,0 +1,67 @@
+/* Fitsy FITS routines to work with the data portion of a FITS file.
+ */
+
+#include <xos.h>
+#include "fitsy.h"
+
+/* Skip over the data part of a FITS header data unit.
+
+   If the file is seekable and the #ofile file pointer is
+   #NULL or nfile is 0, the data are skipped with an #fseek().
+
+   If the #ofile file pointer is #NULL no data is written.
+
+ */
+
+#define NBLOCK	500
+
+off_t ft_dataskip(ifile, fits, ofiles, nofile)
+	File		ifile;	/* File pointer to read FITS data from.	*/
+	FITSHead	fits;	/* FITS header associated with data.	*/
+	File*		ofiles;	/* File pointers to write data to.	*/
+	int		nofile;	/* number of files */
+{
+                int     i;
+		int	blocks;
+		char	block[FT_BLOCK * NBLOCK];
+  		off_t   pos=0;
+
+        if ( ifile == NULL ) 	return pos;
+        if ( fits  == NULL ) 	return pos;
+		
+	if ( ft_seek(fits) != -1 && (!ofiles || !nofile) ) {
+	  if ( ft_databytes(fits) ){
+		pos = ftSeek(ifile, ft_databloks(fits) * FT_BLOCK, 1);
+		return pos;
+	  }
+	}
+
+	if ( ft_databytes(fits) ) {
+	    for ( blocks = ft_databloks(fits);
+		  blocks > NBLOCK; blocks -= NBLOCK ) {
+		ftRead(ifile, block, 1, FT_BLOCK*NBLOCK);
+		for(i=0; i<nofile; i++)
+		    ftWrite(ofiles[i], block, 1, FT_BLOCK*NBLOCK);
+	    }
+	    if ( blocks ) {
+		ftRead(ifile, block, 1, FT_BLOCK*blocks);
+		for(i=0; i<nofile; i++)
+		    ftWrite(ofiles[i], block, 1, FT_BLOCK*blocks);
+	    }
+	}
+	return pos;
+}
+
+/* Seek to the data portion of prevoiusly read fits header data unit.
+ */
+off_t ft_dataseek(sfile, fits)
+	File		sfile;	/* File pointer to seek.	*/
+	FITSHead	fits;
+{
+        if ( sfile == NULL ) 	return -1;
+        if ( fits  == NULL ) 	return -1;
+
+	return ftSeek(sfile, fits->data, 0) != -1;
+}
+
+