errno.c

linux下的聊天程序

#define MAXLINE 4096
#define LISTENQ 1024
#define SA struct sockaddr

#include "curses.h"
#include "stdlib.h"
#include "stdio.h"
#include "errno.h"
#include "netdb.h"
#include "string.h"
#include "sys/time.h"
#include "sys/types.h"
#include "sys/socket.h"
#include "netinet/in.h"
#include "memory.h"
#include "stdarg.h"
#include "syslog.h"
int daemon_proc;

static void err_doit(int errnoflag,int level,const char * fmt,va_list ap)
{
	int errno_save,n;
	char buf[MAXLINE];
	errno_save = errno;
#ifdef HAVE_VSNPRINTF
	vsnprlntf(buf,sizeof(buf),fmt,ap);
#else
	vsprintf(buf,fmt,ap);
#endif
	n = strlen(buf);
	if(errnoflag)
		snprintf(buf + n,sizeof(buf) -n,":%s",strerror(errno_save));
	strcat(buf,"\n");
	if(daemon_proc){
		syslog(level,buf);
	}else{
		fflush(stdout);
		fputs(buf,stderr);
		fflush(stderr);
	}
	return;
}
err_sys(const char * fmt,...)
{
	va_list ap;
	va_start(ap,fmt);
	err_doit(1,LOG_ERR,fmt,ap);
	va_end(ap);
	exit(1);
}
err_quit(const char * fmt,...)
{
	va_list ap;
	va_start(ap,fmt);
	err_doit(0,LOG_ERR,fmt,ap);
	va_end(ap);
	exit(1);
}