2.11BSD/man/cat3/warn.0

ERR(3)		    UNIX Programmer's Manual		   ERR(3)



NAME
     err, verr , errx , verrx , warn , vwarn , warnx , vwarnx -
     formatted error messages

SYNOPSIS
     void
     err(eval, fmt, ...)
	 int eval;
	 char *fmt;

     void
     verr(eval, fmt, args)
	 int eval;
	 char *fmt;
	 va_list args;

     void
     errx(eval, fmt, ...)
	 int eval;
	 char *fmt;

     void
     verrx(eval, fmt, args)
	 int eval
	 char *fmt;
	 va_list args;

     void
     warn(fmt, ...)
	 char *fmt;

     void
     vwarn(fmt, args)
	 char *fmt;
	 va_list args;

     void
     warnx(fmt, ...)
	 char *fmt;

     void
     vwarnx(fmt, args)
	 char *fmt;
	 va_list args;

DESCRIPTION
     The err and warn family of functions display a formatted
     error message on the standard error output.  In all cases,
     the last component of the program name, a colon character,
     and a space are output.  If the _f_m_t argument is not NULL,
     the formatted error message, a colon character, and a space
     are output.  In the case of the err, verr, warn, and vwarn



Printed 11/26/99	February 3, 1995			1






ERR(3)		    UNIX Programmer's Manual		   ERR(3)



     functions, the error message string affiliated with the
     current value of the global variable _e_r_r_n_o is output.  In
     all cases, the output is followed by a newline character.

     The err, verr, errx, and verrx functions do not return, but
     exit with the value of the argument _e_v_a_l.

EXAMPLES
     Display the current errno information string and exit:

	       if ((p = malloc(size)) == NULL)
		    err(1, NULL);
	       if ((fd = open(file_name, O_RDONLY, 0)) == -1)
		    err(1, "%s", file_name);

     Display an error message and exit:

	       if (tm.tm_hour < START_TIME)
		    errx(1, "too early, wait until %s", start_time_string);

     Warn of an error:

	       if ((fd = open(raw_device, O_RDONLY, 0)) == -1)
		    warnx("%s: %s: trying the block device",
			raw_device, strerror(errno));
	       if ((fd = open(block_device, O_RDONLY, 0)) == -1)
		    err(1, "%s", block_device);

SEE ALSO
     strerror(3)

HISTORY
     The err and warn functions first appeared in 4.4BSD.






















Printed 11/26/99	February 3, 1995			2