#include	<errno.h>		/* for definition of errno */#include	<stdarg.h>		/* ANSI C header file */#include	"ourhdr.h"static void	err_doit(int, const char *, va_list);char	*pname = NULL;		/* caller can set this from argv[0] *//* Nonfatal error related to a system call. * Print a message and return. */void/* $f err_ret $ */err_ret(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	err_doit(1, fmt, ap);	va_end(ap);	return;}/* Fatal error related to a system call. * Print a message and terminate. */void/* $f err_sys $ */err_sys(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	err_doit(1, fmt, ap);	va_end(ap);	exit(1);}/* Fatal error related to a system call. * Print a message, dump core, and terminate. */void/* $f err_dump $ */err_dump(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	err_doit(1, fmt, ap);	va_end(ap);	abort();		/* dump core and terminate */	exit(1);		/* shouldn't get here */}/* Nonfatal error unrelated to a system call. * Print a message and return. */void/* $f err_msg $ */err_msg(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	err_doit(0, fmt, ap);	va_end(ap);	return;}/* Fatal error unrelated to a system call. * Print a message and terminate. */void/* $f err_quit $ */err_quit(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	err_doit(0, fmt, ap);	va_end(ap);	exit(1);}/* Print a message and return to caller. * Caller specifies "errnoflag". */static voiderr_doit(int errnoflag, const char *fmt, va_list ap){	int		errno_save;	char	buf[MAXLINE];	errno_save = errno;		/* value caller might want printed */	vsprintf(buf, fmt, ap);	if (errnoflag)		sprintf(buf+strlen(buf), ": %s", strerror(errno_save));	strcat(buf, "\n");	fflush(stdout);		/* in case stdout and stderr are the same */	fputs(buf, stderr);	fflush(stderr);		/* SunOS 4.1.* doesn't grok NULL argument */	return;}