man.postnix Miscellaneous man pages of Plan 9 related material

     PERROR(2)                                               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 describing 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.  Logname must contain no slashes.  The mes-
          sage is a line with several fields: the name of the machine
          writing the message; the date and time; the message speci-
          fied by the print(2) format fmt and any following arguments;
          and a final newline.  If cons is set or the log file cannot
          be opened, the message is also printed on the system con-
          sole.  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 pre-
          ferred.

     Page 1                       Plan 9             (printed 11/9/25)