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STRERROR(3)                 BSD Programmer's Manual                STRERROR(3)

NAME
     perror, strerror, sys_errlist, sys_nerr - system error messages

SYNOPSIS
     #include <&lt;stdio.h>&gt;

     void
     perror(const char *string);

     extern char *sys_errlist[];
     extern int sys_nerr;

     #include <&lt;string.h>&gt;

     char *
     strerror(int errnum);

DESCRIPTION
     The strerror() and perror() functions look up the error message string
     corresponding to an error number.

     The strerror() function accepts an error number argument errnum and re-
     turns a pointer to the corresponding message string.

     The perror() function finds the error message corresponding to the cur-
     rent value of the global variable errno (intro(2))  and writes it, fol-
     lowed by a newline, to the standard error file descriptor.  If the argu-
     ment string is non-NULL, it is prepended to the message string and sepa-
     rated from it by a colon and space (`: '). If string is NULL, only the
     error message string is printed.

     If errnum is not a recognized error number, the error message string will
     contain ``Unknown error: '' followed by the error number in decimal.

     The message strings can be accessed directly using the external array
     sys_errlist. The external value sys_nerr contains a count of the messages
     in sys_errlist. The use of these variables is deprecated; strerror()
     should be used instead.

SEE ALSO
     intro(2),  psignal(3)

HISTORY
     The strerror() and perror() functions first appeared in 4.4BSD.

BUGS
     For unknown error numbers, the strerror() function will return its result
     in a static buffer which may be overwritten by subsequent calls.

4th Berkeley Distribution        June 9, 1993                                1