NAME
SYNOPSIS
DESCRIPTION
The
and
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
argument is not NULL, the
printf(3)
-like formatted error message is output.
The output is terminated by a newline character.
The
and
functions append an error message obtained from
strerror(3)
based on a code or the global variable
preceded by another colon and space unless the
argument is
The
and
functions use the global variable
to look up the error message.
The
and
functions do not append an error message.
The
and
functions do not return, but exit with the value of the argument
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);
CONFORMING TO
These functions are non-standard BSD extensions.
HISTORY
The
and
functions first appeared in
x 4.4 .
SEE ALSO