xref: /original-bsd/local/local.cmd/20b.c (revision 7211505a)
1 /*
2  * Copyright (c) 1986 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 char copyright[] =
20 "@(#) Copyright (c) 1986 Regents of the University of California.\n\
21  All rights reserved.\n";
22 #endif /* not lint */
23 
24 #ifndef lint
25 static char sccsid[] = "@(#)20b.c	5.5 (Berkeley) 06/29/88";
26 #endif /* not lint */
27 
28 #include <stdio.h>
29 
30 main(argc, argv)
31 	int argc;
32 	char **argv;
33 {
34 	register int bsize, cc, want;
35 	register char *base, *current;
36 	char *alloca();
37 
38 	if (argc > 1) {
39 		bsize = atoi(argv[1]);
40 		if (bsize <= 0) {
41 			fputs("20b: bad block size.\n", stderr);
42 			exit(-1);
43 		}
44 	}
45 	else
46 		bsize = 20 * 512;
47 	base = alloca(bsize);
48 	for (cc = bsize; cc > 0;) {
49 		current = base;
50 		for (want = bsize; want > 0 && cc > 0; want -= cc) {
51 			if ((cc = read(0, current, want)) < 0)
52 				return(-1);
53 			current += cc;
54 		}
55 		want = bsize - want;
56 		if (want && write(1, base, want) != want)
57 			return(-1);
58 	}
59 	return(0);
60 }
61