term% cat index.txt PERROR(3) Library Functions Manual PERROR(3)
NAME
perror, sys_errlist, sys_nerr - system error messages
SYNOPSIS
perror(s)
char *s;
int sys_nerr;
char *sys_errlist[];
DESCRIPTION
Perror produces a short error message on the standard error file de‐
scribing the last error encountered during a call to the system from a
C program. First the argument string s is printed, then a colon, then
the message and a new-line. Most usefully, the argument string is the
name of the program which incurred the error. The error number is
taken from the external variable errno (see intro(2)), which is set
when errors occur but not cleared when non-erroneous calls are made.
To simplify variant formatting of messages, the vector of message
strings sys_errlist is provided; errno can be used as an index in this
table to get the message string without the newline. Sys_nerr is the
number of messages provided for in the table; it should be checked be‐
cause new error codes may be added to the system before they are added
to the table.
SEE ALSO
intro(2)
PERROR(3)