xref: /csrg-svn/lib/libc/string/strerror.c (revision 49064)
137340Sbostic /*
237340Sbostic  * Copyright (c) 1988 Regents of the University of California.
337340Sbostic  * All rights reserved.
437340Sbostic  *
542635Sbostic  * %sccs.include.redist.c%
637340Sbostic  */
737340Sbostic 
837340Sbostic #if defined(LIBC_SCCS) && !defined(lint)
9*49064Sbostic static char sccsid[] = "@(#)strerror.c	5.6 (Berkeley) 05/04/91";
1037340Sbostic #endif /* LIBC_SCCS and not lint */
1137340Sbostic 
1242181Sbostic #include <string.h>
1342181Sbostic 
1437340Sbostic char *
15*49064Sbostic strerror(num)
16*49064Sbostic 	int num;
1737340Sbostic {
1837340Sbostic 	extern int sys_nerr;
1937340Sbostic 	extern char *sys_errlist[];
20*49064Sbostic #define	UPREFIX	"Unknown error: "
21*49064Sbostic 	static char ebuf[40] = UPREFIX;		/* 64-bit number + slop */
22*49064Sbostic 	register unsigned int errnum;
23*49064Sbostic 	register char *p, *t;
24*49064Sbostic 	char tmp[40];
2537340Sbostic 
26*49064Sbostic 	errnum = num;				/* convert to unsigned */
27*49064Sbostic 	if (errnum < sys_nerr)
2837340Sbostic 		return(sys_errlist[errnum]);
29*49064Sbostic 
30*49064Sbostic 	/* Do this by hand, so we don't include stdio(3). */
31*49064Sbostic 	t = tmp;
32*49064Sbostic 	do {
33*49064Sbostic 		*t++ = "0123456789"[errnum % 10];
34*49064Sbostic 	} while (errnum /= 10);
35*49064Sbostic 	for (p = ebuf + sizeof(UPREFIX) - 1;;) {
36*49064Sbostic 		*p++ = *--t;
37*49064Sbostic 		if (t <= tmp)
38*49064Sbostic 			break;
39*49064Sbostic 	}
4037340Sbostic 	return(ebuf);
4137340Sbostic }
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