xref: /csrg-svn/usr.bin/f77/libU77/fseek_.c (revision 47944)
1*47944Sbostic /*-
2*47944Sbostic  * Copyright (c) 1980 The Regents of the University of California.
3*47944Sbostic  * All rights reserved.
42530Sdlw  *
5*47944Sbostic  * %sccs.include.proprietary.c%
623015Skre  */
723015Skre 
8*47944Sbostic #ifndef lint
9*47944Sbostic static char sccsid[] = "@(#)fseek_.c	5.2 (Berkeley) 04/12/91";
10*47944Sbostic #endif /* not lint */
11*47944Sbostic 
1223015Skre /*
132530Sdlw  * position a file associated with a fortran logical unit
142530Sdlw  *
152530Sdlw  * calling sequence:
162530Sdlw  *	ierror = fseek(lunit, ioff, ifrom)
172530Sdlw  * where:
182530Sdlw  *	lunit is an open logical unit
192530Sdlw  *	ioff is an offset in bytes relative to the position specified by ifrom
202530Sdlw  *	ifrom	- 0 means 'beginning of the file'
212530Sdlw  *		- 1 means 'the current position'
222530Sdlw  *		- 2 means 'the end of the file'
232530Sdlw  *	ierror will be 0 if successful, a system error code otherwise.
242530Sdlw  */
252530Sdlw 
262530Sdlw #include	<stdio.h>
272530Sdlw #include	"../libI77/f_errno.h"
282530Sdlw #include	"../libI77/fiodefs.h"
292530Sdlw 
302530Sdlw extern unit units[];
312530Sdlw 
fseek_(lu,off,from)322530Sdlw long fseek_(lu, off, from)
332530Sdlw long *lu, *off, *from;
342530Sdlw {
352578Sdlw 	if (*lu < 0 || *lu >= MXUNIT)
362578Sdlw 		return((long)(errno=F_ERUNIT));
372578Sdlw 	if (*from < 0 || *from > 2)
382530Sdlw 		return((long)(errno=F_ERARG));
392530Sdlw 	if (!units[*lu].ufd)
402530Sdlw 		return((long)(errno=F_ERNOPEN));
412530Sdlw 	if (fseek(units[*lu].ufd, *off, (int)*from) < 0)
422530Sdlw 		return((long)errno);
432530Sdlw 	return(0L);
442530Sdlw }
45