#include	<errno.h>		/* for definition of errno */#include	<stdarg.h>		/* ANSI C header file */#include	<stdio.h>#include	<stdlib.h>#include	<string.h>		/* for strerror() */#include	"ourhdr.h"char	*pname = NULL;		/* caller can set this from argv[0] *//* Recoverable error.  Print a message based on the system's * errno value, and return to caller. *//* $[err_ret]~function$ */voiderr_ret(const char *fmt, ...){	va_list		ap;	int			errno_save;	errno_save = errno;		/* value caller wants printed */	fflush(stdout);	va_start(ap, fmt);	if (pname != NULL)		fprintf(stderr, "%s: ", pname);	vfprintf(stderr, fmt, ap);	va_end(ap);	fprintf(stderr, ": %s\n", strerror(errno_save));	fflush(stderr);	return;}/* Fatal error related to a system call.  Print a message and terminate. * Don't dump core, but do print the system's errno value and its * associated message. *//* $[err_sys]~function$ */voiderr_sys(const char *fmt, ...){	va_list		ap;	int			errno_save;	errno_save = errno;		/* value caller wants printed */	fflush(stdout);	va_start(ap, fmt);	if (pname != NULL)		fprintf(stderr, "%s: ", pname);	vfprintf(stderr, fmt, ap);	va_end(ap);	fprintf(stderr, ": %s\n", strerror(errno_save));	fflush(stderr);	exit(1);}/* Fatal error.  Print a message, dump core (for debugging) and terminate. *//* $[err_dump]~function$ */voiderr_dump(const char *fmt, ...){	va_list		ap;	int			errno_save;	errno_save = errno;		/* value caller wants printed */	fflush(stdout);	va_start(ap, fmt);	if (pname != NULL)		fprintf(stderr, "%s: ", pname);	vfprintf(stderr, fmt, ap);	va_end(ap);	fprintf(stderr, ": %s\n", strerror(errno_save));	fflush(stderr);	abort();		/* dump core and terminate */	exit(1);		/* shouldn't get here */}/* Recoverable error.  Print a message, and return to caller. * The system's errno value is not printed. *//* $[err_msg]~function$ */voiderr_msg(const char *fmt, ...){	va_list		ap;	fflush(stdout);	va_start(ap, fmt);	if (pname != NULL)		fprintf(stderr, "%s: ", pname);	vfprintf(stderr, fmt, ap);	va_end(ap);	fflush(stderr);	return;}/* Fatal error.  Print a message and terminate. * Don't dump core and don't print the system's errno value. *//* $[err_quit]~function$ */voiderr_quit(const char *fmt, ...){	va_list		ap;	va_start(ap, fmt);	if (pname != NULL)		fprintf(stderr, "%s: ", pname);	vfprintf(stderr, fmt, ap);	putc('\n', stderr);	va_end(ap);	exit(1);}