xref: /original-bsd/usr.bin/f77/libU77/fseek_.c (revision 2d1a7683)
1 /*-
2  * Copyright (c) 1980 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.proprietary.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)fseek_.c	5.2 (Berkeley) 04/12/91";
10 #endif /* not lint */
11 
12 /*
13  * position a file associated with a fortran logical unit
14  *
15  * calling sequence:
16  *	ierror = fseek(lunit, ioff, ifrom)
17  * where:
18  *	lunit is an open logical unit
19  *	ioff is an offset in bytes relative to the position specified by ifrom
20  *	ifrom	- 0 means 'beginning of the file'
21  *		- 1 means 'the current position'
22  *		- 2 means 'the end of the file'
23  *	ierror will be 0 if successful, a system error code otherwise.
24  */
25 
26 #include	<stdio.h>
27 #include	"../libI77/f_errno.h"
28 #include	"../libI77/fiodefs.h"
29 
30 extern unit units[];
31 
32 long fseek_(lu, off, from)
33 long *lu, *off, *from;
34 {
35 	if (*lu < 0 || *lu >= MXUNIT)
36 		return((long)(errno=F_ERUNIT));
37 	if (*from < 0 || *from > 2)
38 		return((long)(errno=F_ERARG));
39 	if (!units[*lu].ufd)
40 		return((long)(errno=F_ERNOPEN));
41 	if (fseek(units[*lu].ufd, *off, (int)*from) < 0)
42 		return((long)errno);
43 	return(0L);
44 }
45