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 <u.h>
9 #include <errno.h>
10 #include <string.h>
11 #include <libc.h>
12 
13 enum
14 {
15 	EPLAN9 = 0x19283745
16 };
17 
18 char *(*_syserrstr)(void);
19 static char xsyserr[ERRMAX];
20 static char*
21 getsyserr(void)
22 {
23 	char *s;
24 
25 	s = nil;
26 	if(_syserrstr)
27 		s = (*_syserrstr)();
28 	if(s == nil)
29 		s = xsyserr;
30 	return s;
31 }
32 
33 int
34 errstr(char *err, uint n)
35 {
36 	char tmp[ERRMAX];
37 	char *syserr;
38 
39 	strecpy(tmp, tmp+ERRMAX, err);
40 	rerrstr(err, n);
41 	syserr = getsyserr();
42 	strecpy(syserr, syserr+ERRMAX, tmp);
43 	errno = EPLAN9;
44 	return 0;
45 }
46 
47 void
48 rerrstr(char *err, uint n)
49 {
50 	char *syserr;
51 
52 	syserr = getsyserr();
53 	if(errno == EINTR)
54 		strcpy(syserr, "interrupted");
55 	else 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 }