| .TH SYSFATAL 3 |
| .SH NAME |
| syslog, sysfatal \- system error messages |
| .SH SYNOPSIS |
| .B #include <u.h> |
| .br |
| .B #include <libc.h> |
| .PP |
| .B |
| void syslog(int cons, char *logname, char *fmt, ...) |
| .PP |
| .B |
| void sysfatal(char *fmt, ...) |
| .SH DESCRIPTION |
| .I Sysfatal |
| prints to standard error the name of the running program, |
| a colon and a space, |
| the message described by the |
| .IR print (3) |
| format string |
| .I fmt |
| and subsequent arguments, and a newline. |
| It then calls |
| .IR exits (3) |
| with the formatted message as argument. |
| The program's name is the value of |
| .BR argv0 , |
| which will be set if the program uses the |
| .IR arg (3) |
| interface to process its arguments. |
| If |
| .B argv0 |
| is null, it is ignored and the following colon and space are suppressed. |
| .PP |
| .I Syslog |
| logs messages in the file named by |
| .I logname |
| in the directory |
| .B \*9/log ; |
| the file must already exist and is opened append-only. |
| .I Logname |
| must contain no slashes. |
| The message is a line with several fields: |
| the name of the machine writing the message; |
| the date and time; |
| the message specified by the |
| .IR print (3) |
| format |
| .I fmt |
| and any following arguments; |
| and a final newline. |
| If |
| .I cons |
| is set or the log file cannot be opened, the message is also printed |
| on the system console. |
| .I Syslog |
| can be used safely in multi-threaded programs. |
| .SH SOURCE |
| .B \*9/src/lib9/sysfatal.c |
| .br |
| .B \*9/src/lib9/syslog.c |
| .SH "SEE ALSO" |
| .IR intro (3), |
| .IR errstr (3), |
| the |
| .B %r |
| format in |
| .IR print (3) |
