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PERROR(2) System Calls Manual PERROR(2) NAME perror, syslog - system error messages SYNOPSIS #include <u.h> #include <libc.h> void perror(char *s) void syslog(int cons, char *logname, char *fmt, ...) DESCRIPTION Perror produces a short error message on the standard error file de‐ scribing the last error encountered during a call to the system. First the argument string s is printed, then a colon, then the message and a newline. If s is 0, only the error message and newline are printed. Syslog logs messages in the file named by logname in the directory /sys/log; the file must already exist and should be append-only. Log‐ name 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 print(2) format fmt and any following ar‐ guments; and a final newline. If cons is set or the log file cannot be opened, the message is also printed on the system console. Syslog can be used safely in multi-threaded programs. SOURCE /sys/src/libc/port/perror.c /sys/src/libc/9sys/syslog.c SEE ALSO intro(2), errstr(2), the %r format in print(2) BUGS Perror is a holdover; the %r format in print(2) is preferred. PERROR(2)