1 /*
2  * We assume there's only one error buffer for the whole system.
3  * If you use ffork, you need to provide a _syserrstr.  Since most
4  * people will use libthread (which provides a _syserrstr), this is
5  * okay.
6  */
7 
8 #include <errno.h>
9 #include <string.h>
10 #include <lib9.h>
11 
12 enum
13 {
14 	EPLAN9 = 0x19283745,
15 };
16 
17 char *(*_syserrstr)(void);
18 static char xsyserr[ERRMAX];
19 static char*
20 getsyserr(void)
21 {
22 	char *s;
23 
24 	s = nil;
25 	if(_syserrstr)
26 		s = (*_syserrstr)();
27 	if(s == nil)
28 		s = xsyserr;
29 	return s;
30 }
31 
32 int
33 errstr(char *err, uint n)
34 {
35 	char tmp[ERRMAX];
36 	char *syserr;
37 
38 	syserr = getsyserr();
39 	if(errno != EPLAN9)
40 		strcpy(syserr, strerror(errno));
41 
42 	strecpy(tmp, tmp+ERRMAX, syserr);
43 	strecpy(syserr, syserr+ERRMAX, err);
44 	strecpy(err, err+n, tmp);
45 	errno = EPLAN9;
46 	return 0;
47 }
48 
49 void
50 rerrstr(char *err, uint n)
51 {
52 	char *syserr;
53 
54 	syserr = getsyserr();
55 	if(errno != EPLAN9)
56 		strcpy(syserr, strerror(errno));
57 	strecpy(err, err+n, syserr);
58 }
59 
60 /* replaces __errfmt in libfmt */
61 
62 int
63 __errfmt(Fmt *f)
64 {
65 	if(errno == EPLAN9)
66 		return fmtstrcpy(f, getsyserr());
67 	return fmtstrcpy(f, strerror(errno));
68 }
69 
70 void
71 werrstr(char *fmt, ...)
72 {
73 	va_list arg;
74 	char buf[ERRMAX];
75 
76 	va_start(arg, fmt);
77 	vseprint(buf, buf+ERRMAX, fmt, arg);
78 	va_end(arg);
79 	errstr(buf, ERRMAX);
80 }