//實用工具程序之一，作用：將消息轉(zhuǎn)發(fā)給一個備用的郵件地址

#include "sig.h"#include "readwrite.h"#include "exit.h"#include "env.h"#include "qmail.h"#include "strerr.h"#include "substdio.h"#include "fmt.h"#define FATAL "forward: fatal: "void die_nomem() { strerr_die2x(111,FATAL,"out of memory"); }struct qmail qqt;int mywrite(fd,buf,len) int fd; char *buf; int len;{  qmail_put(&qqt,buf,len);  return len;}char inbuf[SUBSTDIO_INSIZE];char outbuf[1];substdio ssin = SUBSTDIO_FDBUF(read,0,inbuf,sizeof inbuf);substdio ssout = SUBSTDIO_FDBUF(mywrite,-1,outbuf,sizeof outbuf);char num[FMT_ULONG];void main(argc,argv)int argc;char **argv;{  char *sender;  char *dtline;  char *qqx;   sig_pipeignore();   sender = env_get("NEWSENDER");  if (!sender)    strerr_die2x(100,FATAL,"NEWSENDER not set");  dtline = env_get("DTLINE");  if (!dtline)    strerr_die2x(100,FATAL,"DTLINE not set");   if (qmail_open(&qqt) == -1)    strerr_die2sys(111,FATAL,"unable to fork: ");  qmail_puts(&qqt,dtline);  if (substdio_copy(&ssout,&ssin) != 0)    strerr_die2sys(111,FATAL,"unable to read message: ");  substdio_flush(&ssout);  num[fmt_ulong(num,qmail_qp(&qqt))] = 0;   qmail_from(&qqt,sender);  while (*++argv) qmail_to(&qqt,*argv);  qqx = qmail_close(&qqt);  if (*qqx) strerr_die2x(*qqx == 'D' ? 100 : 111,FATAL,qqx + 1);  strerr_die2x(0,"forward: qp ",num);}