//實用工具程序之一，作用是產生一個maildir格式的郵箱，
//監控一個用戶的郵件目錄并報告所有的新消息

#include "getln.h"#include "substdio.h"#include "subfd.h"#include "prioq.h"#include "stralloc.h"#include "str.h"#include "exit.h"#include "hfield.h"#include "readwrite.h"#include "open.h"#include "headerbody.h"#include "maildir.h"#define FATAL "maildirwatch: fatal: "void die_nomem() { strerr_die2x(111,FATAL,"out of memory"); }stralloc recipient = {0};stralloc sender = {0};stralloc fromline = {0};stralloc text = {0};void addtext(s,n) char *s; int n;{ if (!stralloc_catb(&text,s,n)) die_nomem(); if (text.len > 158) text.len = 158;}void dobody(h) stralloc *h; { addtext(h->s,h->len); }void doheader(h) stralloc *h;{ int i; switch(hfield_known(h->s,h->len))  {   case H_SUBJECT:     i = hfield_skipname(h->s,h->len);     addtext(h->s + i,h->len - i);     break;   case H_DELIVEREDTO:     i = hfield_skipname(h->s,h->len);     if (i < h->len)       if (!stralloc_copyb(&recipient,h->s + i,h->len - i - 1)) die_nomem();     break;   case H_RETURNPATH:     i = hfield_skipname(h->s,h->len);     if (i < h->len)       if (!stralloc_copyb(&sender,h->s + i,h->len - i - 1)) die_nomem();     break;   case H_FROM:     if (!stralloc_copyb(&fromline,h->s,h->len - 1)) die_nomem();     break;  }}void finishheader() { ; }stralloc filenames = {0};prioq pq = {0};char inbuf[SUBSTDIO_INSIZE];substdio ssin;void main(){ struct prioq_elt pe; int fd; int i; if (maildir_chdir() == -1)   strerr_die1(111,FATAL,&maildir_chdir_err); for (;;)  {   maildir_clean(&filenames);   if (maildir_scan(&pq,&filenames,1,0) == -1)     strerr_die1(111,FATAL,&maildir_scan_err);   substdio_putsflush(subfdout,"\033[;H\033[;J");   while (prioq_min(&pq,&pe))    {     prioq_delmin(&pq);     fd = open_read(filenames.s + pe.id);     if (fd == -1) continue;     substdio_fdbuf(&ssin,read,fd,inbuf,sizeof(inbuf));     if (!stralloc_copys(&sender,"?")) die_nomem();     if (!stralloc_copys(&recipient,"?")) die_nomem();     if (!stralloc_copys(&fromline,"")) die_nomem();     if (!stralloc_copys(&text,"")) die_nomem();     if (headerbody(&ssin,doheader,finishheader,dobody) == -1)       strerr_die2x(111,FATAL,"trouble reading new message");     for (i = 0;i < fromline.len;++i)       if ((fromline.s[i] < 32) || (fromline.s[i] > 126))         fromline.s[i] = '/';     for (i = 0;i < sender.len;++i)       if ((sender.s[i] < 32) || (sender.s[i] > 126))         sender.s[i] = '?';     for (i = 0;i < recipient.len;++i)       if ((recipient.s[i] < 32) || (recipient.s[i] > 126))         recipient.s[i] = '?';     for (i = 0;i < text.len;++i)       if ((text.s[i] < 32) || (text.s[i] > 126))         text.s[i] = '/';     substdio_puts(subfdout,"FROM ");     substdio_put(subfdout,sender.s,sender.len);     substdio_puts(subfdout," TO <");     substdio_put(subfdout,recipient.s,recipient.len);     substdio_puts(subfdout,">\n");     if (fromline.len)      {       substdio_puts(subfdout,"\033[1m");       substdio_put(subfdout,fromline.s,fromline.len);       substdio_puts(subfdout,"\033[0m\n");      }     substdio_put(subfdout,text.s,text.len);     substdio_puts(subfdout,"\n\n");     close(fd);    }   substdio_flush(subfdout);   sleep(30);  }}