1 .TH SYSFATAL 3
2 .SH NAME
3 syslog, sysfatal \- system error messages
4 .SH SYNOPSIS
5 .B #include <u.h>
6 .br
7 .B #include <libc.h>
8 .PP
9 .B
10 void syslog(int cons, char *logname, char *fmt, ...)
11 .PP
12 .B
13 void sysfatal(char *fmt, ...)
14 .SH DESCRIPTION
15 .I Sysfatal
16 prints to standard error the name of the running program,
17 a colon and a space, 
18 the message described by the
19 .MR print (3)
20 format string
21 .I fmt
22 and subsequent arguments, and a newline.
23 It then calls
24 .MR exits (3)
25 with the formatted message as argument.
26 The program's name is the value of
27 .BR argv0 ,
28 which will be set if the program uses the
29 .MR arg (3)
30 interface to process its arguments.
31 If
32 .B argv0
33 is null, it is ignored and the following colon and space are suppressed.
34 .PP
35 .I Syslog
36 logs messages in the file named by
37 .I logname
38 in the directory
39 .B \*9/log ;
40 the file must already exist and is opened append-only.
41 .I Logname
42 must contain no slashes.
43 The message is a line with several fields:
44 the name of the machine writing the message;
45 the date and time;
46 the message specified by the 
47 .MR print (3)
48 format
49 .I fmt
50 and any following arguments;
51 and a final newline.
52 If
53 .I cons
54 is set or the log file cannot be opened, the message is also printed
55 on the system console.
56 .I Syslog
57 can be used safely in multi-threaded programs.
58 .SH SOURCE
59 .B \*9/src/lib9/sysfatal.c
60 .br
61 .B \*9/src/lib9/syslog.c
62 .SH "SEE ALSO"
63 .MR intro (3) ,
64 .MR errstr (3) ,
65 the
66 .B %r
67 format in
68 .MR print (3)