verrx() -- write error message to standard error and exit

SYNOPSIS

#include <err.h>

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

The function verrx() writes a formatted error message to the standard error stream, then exits with the specified error value. The first part of the output line sent to standard error consists of the file name of the executable, followed by a colon and a space. If the value of fmt is not null, this is followed by a message containing the optional variables, formatted according to fmt, followed by a trailing colon and space. The output line is terminated by a linefeed.

The function verrx() is roughly equivalent to

fprintf(stderr,"%s: ", argv[0]);
vfprintf(stderr, fmt, vargs);
fprintf(stderr, "\n");
exit(eval);

PARAMETERS

eval: Is the exit value for process.
fmt: Is the format string for optional arguments, or the null pointer if no formatted message is to be written.
vargs: Are optional arguments to the formatted message.