PERROR(3)PERROR(3)NAME
perror, strerror, sys_errlist, sys_nerr - system error messages
SYNOPSISperror(string)
char *string;
char *
strerror(errnum)
int errnum;
extern int errno, sys_nerr;
extern char *sys_errlist[];
DESCRIPTION
Perror produces a short error message on the standard error file
describing the last error encountered during a call to the system from
a C program. If string is non-NULL, it is printed, followed by a
colon, followed by a space, followed by the message and a new-line.
Otherwise, just the message and the new-line are printed. Most use‐
fully, 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 strerror function
returns a pointer to the error message string mapped to the error num‐
ber errnum.
The message strings can be accessed directly using the external charac‐
ter array sys_errlist. Sys_nerr is the total number of messages in the
array. The use of these variables is deprecated; strerror should be
used instead.
SEE ALSOintro(2)4th Berkeley Distribution June 24, 1990 PERROR(3)