strerror_r(3)                                             strerror_r(3)

  strerror()

  NAME

    perror(), strerror(), strerror_r(), hstrerror(), - system error messages

  SYNOPSIS

    #include 

    void perror (const char *string)

    #include 

    char * strerror (int errnum)
    int strerror_r (int errnum, char *strerrbuf, size_t buflen)
    char * hstrerror (int errnum)

  DESCRIPTION

    The strerror(3) and perror(3) functions look up the error message string
    corresponding to an error number.

    The strerror(3) function accepts an error number argument errnum and
    returns a pointer to the corresponding message string.

    The reentrant strerror_r(3) function maps the error number specified by
    errnum to a locale-dependent error message string and shall returns the
    string in the buffer identified by strerrbuf, with length buflen.

    The perror(3) function finds the error message corresponding to the
    current value of the global variable errno (see the errors(1) page) and
    writes it, followed by a newline, to the standard error file descriptor.
    If the argument string is non-NULL, it is prepended to the message string
    and separated 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 hstrerror(3) call is a #define for strerror(3), provided for
    convenience in working with sockets.

  SEE ALSO

    errno(3)

  USAGE NOTES

    The following functions are thread safe: perror, strerror_r. The following
    functions are not thread safe: strerror, hstrerror.

    None of these functions are async-signal safe.