1 /*
2 Plan 9 from User Space src/lib9/errstr.c
3 http://code.swtch.com/plan9port/src/tip/src/lib9/errstr.c
4
5 Copyright 2001-2007 Russ Cox. All Rights Reserved.
6
7 Permission is hereby granted, free of charge, to any person obtaining a copy
8 of this software and associated documentation files (the "Software"), to deal
9 in the Software without restriction, including without limitation the rights
10 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 copies of the Software, and to permit persons to whom the Software is
12 furnished to do so, subject to the following conditions:
13
14 The above copyright notice and this permission notice shall be included in
15 all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 THE SOFTWARE.
24 */
25
26 /*
27 * We assume there's only one error buffer for the whole system.
28 * If you use ffork, you need to provide a _syserrstr. Since most
29 * people will use libthread (which provides a _syserrstr), this is
30 * okay.
31 */
32
33 #include <u.h>
34 #include <errno.h>
35 #include <string.h>
36 #include <libc.h>
37
38 enum
39 {
40 EPLAN9 = 0x19283745
41 };
42
43 char *(*_syserrstr)(void);
44 static char xsyserr[ERRMAX];
45 static char*
46 getsyserr(void)
47 {
48 char *s;
49
50 s = nil;
51 if(_syserrstr)
52 s = (*_syserrstr)();
53 if(s == nil)
54 s = xsyserr;
55 return s;
56 }
57
58 int
59 errstr(char *err, uint n)
60 {
61 char tmp[ERRMAX];
62 char *syserr;
63
64 strecpy(tmp, tmp+ERRMAX, err);
65 rerrstr(err, n);
66 syserr = getsyserr();
67 strecpy(syserr, syserr+ERRMAX, tmp);
68 errno = EPLAN9;
69 return 0;
70 }
71
72 void
73 rerrstr(char *err, uint n)
74 {
75 char *syserr;
76
77 syserr = getsyserr();
78 if(errno == EINTR)
79 strcpy(syserr, "interrupted");
80 else if(errno != EPLAN9)
81 strcpy(syserr, strerror(errno));
82 strecpy(err, err+n, syserr);
83 }
84
85 /* replaces __errfmt in libfmt */
86
87 int
88 __errfmt(Fmt *f)
89 {
90 if(errno == EPLAN9)
91 return fmtstrcpy(f, getsyserr());
92 return fmtstrcpy(f, strerror(errno));
93 }
94
95 void
96 werrstr(char *fmt, ...)
97 {
98 va_list arg;
99 char buf[ERRMAX];
100
101 va_start(arg, fmt);
102 vseprint(buf, buf+ERRMAX, fmt, arg);
103 va_end(arg);
104 errstr(buf, ERRMAX);
105 }
106