qmail-local代码分析

我分析的代码没有“夜未眠”大哥的好，可能还有的不正确，就请各位多多指教，谢谢

代码:

#include <sys/types.h>

#include <sys/stat.h>

#include "readwrite.h"

#include "sig.h"

#include "env.h"

#include "byte.h"

#include "exit.h"

#include "fork.h"

#include "open.h"

#include "wait.h"

#include "lock.h"

#include "seek.h"

#include "substdio.h"

#include "getln.h"

#include "strerr.h"

#include "subfd.h"

#include "sgetopt.h"

#include "alloc.h"

#include "error.h"

#include "stralloc.h"

#include "fmt.h"

#include "str.h"

#include "now.h"

#include "case.h"

#include "quote.h"

#include "qmail.h"

#include "slurpclose.h"

#include "myctime.h"

#include "gfrom.h"

#include "auto_patrn.h"

void usage() { strerr_die1x(100,"qmail-local: usage: qmail-local [ -nN ] user homedir local dash ext domain sender aliasempty"); }

void temp_nomem() { strerr_die1x(111,"Out of memory. (#4.3.0)"); }

void temp_rewind() { strerr_die1x(111,"Unable to rewind message. (#4.3.0)"); }

void temp_childcrashed() { strerr_die1x(111,"Aack, child crashed. (#4.3.0)"); }

void temp_fork() { strerr_die3x(111,"Unable to fork: ",error_str(errno),". (#4.3.0)"); }

void temp_read() { strerr_die3x(111,"Unable to read message: ",error_str(errno),". (#4.3.0)"); }

void temp_slowlock()

{ strerr_die1x(111,"File has been locked for 30 seconds straight. (#4.3.0)"); }

void temp_qmail(fn) char *fn;

{ strerr_die5x(111,"Unable to open ",fn,": ",error_str(errno),". (#4.3.0)"); }

int flagdoit;

int flag99;

char *user;

char *homedir;

char *local;

char *dash;

char *ext;

char *host;

char *sender;

char *aliasempty;

stralloc safeext = {0};

stralloc ufline = {0};

stralloc rpline = {0};

stralloc envrecip = {0};

stralloc dtline = {0};

stralloc qme = {0};

stralloc ueo = {0};

stralloc cmds = {0};

stralloc messline = {0};

stralloc foo = {0};

char buf[1024];

char outbuf[1024];

/* child process */

char fntmptph[80 + FMT_ULONG * 2];

char fnnewtph[80 + FMT_ULONG * 2];

void tryunlinktmp() { unlink(fntmptph); }/*删除fntmptph文件，或连接*/

void sigalrm() { tryunlinktmp(); _exit(3); }

void maildir_child(dir)

char *dir;

{

unsigned long pid;

unsigned long time;

char host[64];

char *s;

int loop;

strUCt stat st;

int fd;

substdio ss;

substdio ssout;

sig_alarmcatch(sigalrm);//捕捉时间信号。

if (chdir(dir) == -1) { if (error_temp(errno)) _exit(1); _exit(2); }

pid = getpid();//获取当前的进程号。

host[0] = 0;

gethostname(host,sizeof(host));

for (loop = 0;;++loop)

{

time = now();

s = fntmptph;

s += fmt_str(s,"tmp/");/*将"tmp/"拷到s中*/

s += fmt_ulong(s,time); *s++ = '.';/*将时间转化为字符串*/

s += fmt_ulong(s,pid); *s++ = '.';

s += fmt_strn(s,host,sizeof(host)); *s++ = 0;

if (stat(fntmptph,&st) == -1) if (errno == error_noent) break;

/* really should never get to this point */

if (loop == 2) _exit(1);

sleep(2);

}

str_copy(fnnewtph,fntmptph);

byte_copy(fnnewtph,3,"new");

//时间为24小时

alarm(86400);

fd = open_excl(fntmptph);

if (fd == -1) _exit(1);

///////////////////////////////////////////////////

substdio_fdbuf(&ss,read,0,buf,sizeof(buf));

substdio_fdbuf(&ssout,write,fd,outbuf,sizeof(outbuf));

//dtline:邮件头Delivered-To部分

//rpline:邮件头返回路径

//无需"From "头部

if (substdio_put(&ssout,rpline.s,rpline.len) == -1) goto fail;

if (substdio_put(&ssout,dtline.s,dtline.len) == -1) goto fail;

//将邮件写到文件fd中

switch(substdio_copy(&ssout,&ss))

{

case -2: tryunlinktmp(); _exit(4);

case -3: goto fail;

}

if (substdio_flush(&ssout) == -1) goto fail;

//将fd所指文件数据由系统缓冲区写回磁盘正确返回0，错误返回-1

if (fsync(fd) == -1) goto fail;

if (close(fd) == -1) goto fail; /* NFS dorks */

if (link(fntmptph,fnnewtph) == -1) goto fail;

/* if it was error_exist, almost certainly successful; i hate NFS */

tryunlinktmp(); _exit(0);

fail: tryunlinktmp(); _exit(1);

}

/* end child process */

//maildir 格式邮箱的邮件投递，不要锁定

void maildir(fn)

char *fn;

{

int child;

int wstat;

//#define seek_begin(fd) (seek_set((fd),(seek_pos) 0))

//指向文件0的开头

if (seek_begin(0) == -1) temp_rewind();

switch(child = fork())

{

case -1:

temp_fork();

case 0:

maildir_child(fn);/////////////////////////////////////

_exit(111);

}

//返回子进程fd的结束状态值于wstat中

wait_pid(&wstat,child);

//#define wait_crashed(w) ((w) & 127)

if (wait_crashed(wstat))

temp_childcrashed();

//#define wait_exitcode(w) ((w) >> 8)

switch(wait_exitcode(wstat))

{

case 0: break;

case 2: strerr_die1x(111,"Unable to chdir to maildir. (#4.2.1)");

case 3: strerr_die1x(111,"Timeout on maildir delivery. (#4.3.0)");

case 4: strerr_die1x(111,"Unable to read message. (#4.3.0)");

default: strerr_die1x(111,"Temporary error on maildir delivery. (#4.3.0)");

}

}

//mbox 格式邮箱的邮件投递，必须锁定

void mailfile(fn)

char *fn;

{

int fd;

substdio ss;

substdio ssout;

int match;

seek_pos pos;

int flaglocked;

//到文件0开头

if (seek_begin(0) == -1) temp_rewind();

//打开文件fn

fd = open_append(fn);

if (fd == -1)

strerr_die5x(111,"Unable to open ",fn,": ",error_str(errno),". (#4.2.1)");

//时间信号，30秒

sig_alarmcatch(temp_slowlock);

alarm(30);

//锁定

flaglocked = (lock_ex(fd) != -1);

alarm(0);

sig_alarmdefault();

//结尾

seek_end(fd);

//pos实际指向文件尾（文件大小）

pos = seek_cur(fd);

substdio_fdbuf(&ss,read,0,buf,sizeof(buf));

substdio_fdbuf(&ssout,write,fd,outbuf,sizeof(outbuf));

//dtline:邮件头Delivered-To部分

//rpline:邮件头返回路径

//ufline:mbox 是标准的UNIX邮箱格式, 多个邮件存放在一个独立文件内, 每个邮件由一个"From" 的行开始.

//这一行看起来像一个标题字段, 不过那不是标题, 那仅仅是传送代理添加的, 便于邮件读出器可以找到每个邮件开始部分的一个标记.

if (substdio_put(&ssout,ufline.s,ufline.len)) goto writeerrs;

if (substdio_put(&ssout,rpline.s,rpline.len)) goto writeerrs;

if (substdio_put(&ssout,dtline.s,dtline.len)) goto writeerrs;

for (;;)

{//读一行

if (getln(&ss,&messline,&match,'\n') != 0)

{

strerr_warn3("Unable to read message: ",error_str(errno),". (#4.3.0)",0);

if (flaglocked) seek_trunc(fd,pos); close(fd);

_exit(111);

}

if (!match && !messline.len) break;

if (gfrom(messline.s,messline.len))

if (substdio_bput(&ssout,">",1)) goto writeerrs;

if (substdio_bput(&ssout,messline.s,messline.len)) goto writeerrs;

if (!match)

{

if (substdio_bputs(&ssout,"\n")) goto writeerrs;

break;

}

}

if (substdio_bputs(&ssout,"\n")) goto writeerrs;

if (substdio_flush(&ssout)) goto writeerrs;

//由缓冲区写回磁盘

if (fsync(fd) == -1) goto writeerrs;

close(fd);

return;

writeerrs:

strerr_warn5("Unable to write ",fn,": ",error_str(errno),". (#4.3.0)",0);

if (flaglocked) seek_trunc(fd,pos);

close(fd);

_exit(111);

}

void mailprogram(prog)

char *prog;

{

int child;

char *(args[4]);

int wstat;

if (seek_begin(0) == -1) temp_rewind();

switch(child = fork())

{

case -1:

temp_fork();

case 0:

args[0] = "/bin/sh"; args[1] = "-c"; args[2] = prog; args[3] = 0;

sig_pipedefault();

execv(*args,args);

strerr_die3x(111,"Unable to run /bin/sh: ",error_str(errno),". (#4.3.0)");

}

wait_pid(&wstat,child);

if (wait_crashed(wstat))

temp_childcrashed();

switch(wait_exitcode(wstat))

{

case 100:

case 64: case 65: case 70: case 76: case 77: case 78: case 112: _exit(100);

case 0: break;

case 99: flag99 = 1; break;

default: _exit(111);

}

}

unsigned long mailforward_qp = 0;

//转发邮件，地址在recips中

void mailforward(recips)

char **recips;

{//struct qmail {

// int flagerr;

// unsigned long pid;

// int fdm;

// int fde;

// substdio ss;

// char buf[1024];

// } ;

struct qmail QQt;

char *qqx;

substdio ss;

int match;

if (seek_begin(0) == -1) temp_rewind();

substdio_fdbuf(&ss,read,0,buf,sizeof(buf));

if (qmail_open(&qqt) == -1) temp_fork();

mailforward_qp = qmail_qp(&qqt);

qmail_put(&qqt,dtline.s,dtline.len);

do

{

if (getln(&ss,&messline,&match,'\n') != 0) { qmail_fail(&qqt); break; }

qmail_put(&qqt,messline.s,messline.len);

}

while (match);

qmail_from(&qqt,ueo.s);

while (*recips) qmail_to(&qqt,*recips++);

qqx = qmail_close(&qqt);

if (!*qqx) return;

strerr_die3x(*qqx == 'D' ? 100 : 111,"Unable to forward message: ",qqx + 1,".");

}

void bouncexf()

{

int match;

substdio ss;

//#define seek_begin(fd) (seek_set((fd),(seek_pos) 0))

//typedef unsigned long seek_pos

//将文件0的指针移到开始位置。

if (seek_begin(0) == -1) temp_rewind();

//给ss附值，ss->x=buf,s->fd = 0;s->op = read;s->p = 0(字节数);s->n = sizeof(buf)(还有的空间)

substdio_fdbuf(&ss,read,0,buf,sizeof(buf));

for (;;)

{

if (getln(&ss,&messline,&match,'\n') != 0) temp_read();

if (!match) break;

//判定文件是否结束

if (messline.len <= 1)

break;

if (messline.len == dtline.len)

if (!str_diffn(messline.s,dtline.s,dtline.len))

strerr_die1x(100,"This message is looping: it already has my Delivered-To line. (#5.4.6)");

}

}

void checkhome()

{

struct stat st;

if (stat(".",&st) == -1)

strerr_die3x(111,"Unable to stat home Directory: ",error_str(errno),". (#4.3.0)");

if (st.st_mode & auto_patrn)

strerr_die1x(111,"Uh-oh: home directory is writable. (#4.7.0)");

if (st.st_mode & 01000)

if (flagdoit)

strerr_die1x(111,"Home directory is sticky: user is editing his .qmail file. (#4.2.1)");

else

strerr_warn1("Warning: home directory is sticky.",0);

}

//得到文件".qmail"+dash+safeext+dashowner的权限，正确返回0，错误为-1

int qmeox(dashowner)

char *dashowner;

{

struct stat st;

if (!stralloc_copys(&qme,".qmail")) temp_nomem();

if (!stralloc_cats(&qme,dash)) temp_nomem();

if (!stralloc_cat(&qme,&safeext)) temp_nomem();

if (!stralloc_cats(&qme,dashowner)) temp_nomem();

if (!stralloc_0(&qme)) temp_nomem();

if (stat(qme.s,&st) == -1)

{

if (error_temp(errno)) temp_qmail(qme.s);

return -1;

}

return 0;

}

//qme文件存在且是一般文件返回1，否则为0

int qmeexists(fd,cutable)

int *fd;

int *cutable;

{

struct stat st;

if (!stralloc_0(&qme)) temp_nomem();

*fd = open_read(qme.s);

if (*fd == -1) {

if (error_temp(errno)) temp_qmail(qme.s);

if (errno == error_perm) temp_qmail(qme.s);

if (errno == error_acces) temp_qmail(qme.s);

return 0;

}

if (fstat(*fd,&st) == -1) temp_qmail(qme.s);

//S_IFREG表示一般文件

if ((st.st_mode & S_IFMT) == S_IFREG) {

if (st.st_mode & auto_patrn)

strerr_die1x(111,"Uh-oh: .qmail file is writable. (#4.7.0)");

*cutable = !!(st.st_mode & 0100);//看文件的owner权限是否为可执行的。是*cutable = 1，不是*cutable = 0

return 1;

}

close(*fd);

return 0;

}

/* "" "": "" */

/* "-/" "": "-/" "-/default" */

/* "-/" "a": "-/a" "-/default" */

/* "-/" "a-": "-/a-" "-/a-default" "-/default" */

/* "-/" "a-b": "-/a-b" "-/a-default" "-/default" */

/* "-/" "a-b-": "-/a-b-" "-/a-b-default" "-/a-default" "-/default" */

/* "-/" "a-b-c": "-/a-b-c" "-/a-b-default" "-/a-default" "-/default" */

//打开文件&qme，如是一般文件再看是否为default,假如是，"DEFAULT"+*(ext+i)结合加入

void qmesearch(fd,cutable)

int *fd;

int *cutable;

{

int i;

if (!stralloc_copys(&qme,".qmail")) temp_nomem();

if (!stralloc_cats(&qme,dash)) temp_nomem();

if (!stralloc_cat(&qme,&safeext)) temp_nomem();

if (qmeexists(fd,cutable)) {

if (safeext.len >= 7) {

i = safeext.len - 7;

if (!byte_diff("default",7,safeext.s + i))

if (i <= str_len(ext)) /* paranoia */

if (!env_put2("DEFAULT",ext + i)) temp_nomem();

}

return;

}

for (i = safeext.len;i >= 0;--i)

if (!i (safeext.s[i - 1] == '-')) {

if (!stralloc_copys(&qme,".qmail")) temp_nomem();

if (!stralloc_cats(&qme,dash)) temp_nomem();

if (!stralloc_catb(&qme,safeext.s,i)) temp_nomem();

if (!stralloc_cats(&qme,"default")) temp_nomem();

if (qmeexists(fd,cutable)) {

if (i <= str_len(ext)) /* paranoia */

if (!env_put2("DEFAULT",ext + i)) temp_nomem();

return;

}

}

*fd = -1;

}

unsigned long count_file = 0;

unsigned long count_forward = 0;

unsigned long count_program = 0;

char count_buf[FMT_ULONG];

void count_print()

{

substdio_puts(subfdoutsmall,"did ");

substdio_put(subfdoutsmall,count_buf,fmt_ulong(count_buf,count_file));

substdio_puts(subfdoutsmall,"+");

substdio_put(subfdoutsmall,count_buf,fmt_ulong(count_buf,count_forward));

substdio_puts(subfdoutsmall,"+");

substdio_put(subfdoutsmall,count_buf,fmt_ulong(count_buf,count_program));

substdio_puts(subfdoutsmall,"\n");

if (mailforward_qp)

{

substdio_puts(subfdoutsmall,"qp ");

substdio_put(subfdoutsmall,count_buf,fmt_ulong(count_buf,mailforward_qp));

substdio_puts(subfdoutsmall,"\n");

}

substdio_flush(subfdoutsmall);

}

void sayit(type,cmd,len)

char *type;

char *cmd;

int len;

{

substdio_puts(subfdoutsmall,type);

substdio_put(subfdoutsmall,cmd,len);

substdio_putsflush(subfdoutsmall,"\n");

}

void main(argc,argv)

int argc;

char **argv;

{

int opt;

int i;

int j;

int k;

int fd;

int numforward;

char **recips;

datetime_sec starttime;

int flagforwardonly;

char *x;

umask(077);//将系统umask值设为077&0777的值。open函数的真正权限为mode&-umask

sig_pipeignore();//忽略信号

//将environ空间扩大（加10个字符串位置）错误返回0

if (!env_init()) temp_nomem();

//-n Instead of reading and delivering the message, print a description of

// the delivery instructions. (man page)

//-N 是默认值

flagdoit = 1;

while ((opt = getopt(argc,argv,"nN")) != opteof)

switch(opt)

{

case 'n': flagdoit = 0; break;

case 'N': flagdoit = 1; break;

default:

usage();

}

argc -= optind;

argv += optind;

//将参数拷到相应的变量中。

if (!(user = *argv++)) usage();

if (!(homedir = *argv++)) usage();

if (!(local = *argv++)) usage();

if (!(dash = *argv++)) usage();

if (!(ext = *argv++)) usage();

if (!(host = *argv++)) usage();

if (!(sender = *argv++)) usage();

if (!(aliasempty = *argv++)) usage();

if (*argv) usage();

//目录是以'/'开头的

if (homedir[0] != '/') usage();

if (chdir(homedir) == -1)

strerr_die5x(111,"Unable to switch to ",homedir,": ",error_str(errno),". (#4.3.0)");

checkhome();

//将"HOST"和host结合为"HOST="+host，加到environ后面。下同

if (!env_put2("HOST",host)) temp_nomem();//接收地址的域名部分

if (!env_put2("HOME",homedir)) temp_nomem();//用户的主目录

if (!env_put2("USER",user)) temp_nomem();//当前的用户

if (!env_put2("LOCAL",local)) temp_nomem();//接收地址的local部分

//将本地的地址扩展。如local为"dingwenbin",host为pact518.hit.edu.cn,则envrecip为"dingwenbin@pact518.hit.edu.cn"

if (!stralloc_copys(&envrecip,local)) temp_nomem();

if (!stralloc_cats(&envrecip,"@")) temp_nomem();

if (!stralloc_cats(&envrecip,host)) temp_nomem();

//将envrecip->s加'Z'拷到foo->s.

if (!stralloc_copy(&foo,&envrecip)) temp_nomem();

//#define stralloc_0(sa) stralloc_append(sa,"")

//GEN_ALLOC_append(stralloc,char,s,len,a,i,n,x,30,stralloc_readyplus,stralloc_append)

//struct stralloc{char *s;int len;int a;},len是s的长度，a是总共分配的空间。

//stralloc_ready(x,n)作用是：x没有分配空间就分配n大小空间。已分配了且空间小于n就扩大空间

//stralloc_readyplus(x,n)作用是：x没有分配空间就分配n大小空间。分配给x的空间小于x->len+n,就扩大空间

if (!stralloc_0(&foo)) temp_nomem();

//将"RECIPIENT"和foo.s结合为"RECIPIENT="+foo.s，加到environ后面。下同

//信封上接收者的地址

if (!env_put2("RECIPIENT",foo.s)) temp_nomem();

//邮件头Delivered-To部分

if (!stralloc_copys(&dtline,"Delivered-To: ")) temp_nomem();

if (!stralloc_cat(&dtline,&envrecip)) temp_nomem();

for (i = 0;i < dtline.len;++i) if (dtline.s[i] == '\n') dtline.s[i] = '_';

if (!stralloc_cats(&dtline,"\n")) temp_nomem();

if (!stralloc_copy(&foo,&dtline)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

if (!env_put2("DTLINE",foo.s)) temp_nomem();

if (flagdoit)

bouncexf();

//将"SENDER"和sender结合为"SENDER="+sender，加到environ后面。

// 信封上发送者地址

if (!env_put2("SENDER",sender)) temp_nomem();

//将"RPLINE"和"Return-Path:<"+"SENDER"+sender+">\n"结合后加入environ

if (!quote2(&foo,sender)) temp_nomem();

if (!stralloc_copys(&rpline,"Return-Path: <")) temp_nomem();

if (!stralloc_cat(&rpline,&foo)) temp_nomem();

for (i = 0;i < rpline.len;++i) if (rpline.s[i] == '\n') rpline.s[i] = '_';

if (!stralloc_cats(&rpline,">\n")) temp_nomem();

if (!stralloc_copy(&foo,&rpline)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

//邮件头返回路径

if (!env_put2("RPLINE",foo.s)) temp_nomem();

//将"From"+*sender拷到ufline中。*sender为空，则将"From"+"MAILER-DAEMON"拷进去

if (!stralloc_copys(&ufline,"From ")) temp_nomem();

if (*sender)

{

int len; int i; char ch;

len = str_len(sender);

if (!stralloc_readyplus(&ufline,len)) temp_nomem();

for (i = 0;i < len;++i)

{

ch = sender[i];

if ((ch == ' ') (ch == '\t') (ch == '\n')) ch = '-';

ufline.s[ufline.len + i] = ch;

}

ufline.len += len;

}

else

if (!stralloc_cats(&ufline,"MAILER-DAEMON")) temp_nomem();

if (!stralloc_cats(&ufline," ")) temp_nomem();

//在ufline后面加上现在时间。

starttime = now();

if (!stralloc_cats(&ufline,myctime(starttime))) temp_nomem();

if (!stralloc_copy(&foo,&ufline)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

//UUCP风格的"From"行它包含消息所参与的UUCP大宗

//路径形式的路由、最后一台接收消息的机器处理消息的时间和日期以及一

//指明从哪台主机接收来的可选部分。由于每个处理过这个消息的系统都会生成这个字段，所

//以它通常包括在信封数据下。

if (!env_put2("UFLINE",foo.s)) temp_nomem();

//到空行的作用是：假如ext为"aa-bb-cc-dd",则依次把"EXT=aa-bb-cc-dd"，"EXT2=bb-cc-dd","EXT3=cc-dd","EXT4=dd"加入

//地址扩展

x = ext;

if (!env_put2("EXT",x)) temp_nomem();

x += str_chr(x,'-'); if (*x) ++x;

if (!env_put2("EXT2",x)) temp_nomem();

x += str_chr(x,'-'); if (*x) ++x;

if (!env_put2("EXT3",x)) temp_nomem();

x += str_chr(x,'-'); if (*x) ++x;

if (!env_put2("EXT4",x)) temp_nomem();

if (!stralloc_copys(&safeext,ext)) temp_nomem();

//将safeext中字符串转化为小写的

case_lowerb(safeext.s,safeext.len);

for (i = 0;i < safeext.len;++i)

if (safeext.s[i] == '.')

safeext.s[i] = ':';

//例如host为202.18.236.150,则"HOST2=202.18.236","HOST3=202.18","HOST4=202",加入其中

//接收地址的域名部分

i = str_len(host);

i = byte_rchr(host,i,'.');

if (!stralloc_copyb(&foo,host,i)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

if (!env_put2("HOST2",foo.s)) temp_nomem();

i = byte_rchr(host,i,'.');

if (!stralloc_copyb(&foo,host,i)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

if (!env_put2("HOST3",foo.s)) temp_nomem();

i = byte_rchr(host,i,'.');

if (!stralloc_copyb(&foo,host,i)) temp_nomem();

if (!stralloc_0(&foo)) temp_nomem();

if (!env_put2("HOST4",foo.s)) temp_nomem();

flagforwardonly = 0;

qmesearch(&fd,&flagforwardonly);

if (fd == -1)/*文件没打开*/

if (*dash)

strerr_die1x(100,"Sorry, no mailbox here by that name. (#5.1.1)");

if (!stralloc_copys(&ueo,sender)) temp_nomem();

if (str_diff(sender,""))/*sender不空*/

if (str_diff(sender,"#@[]"))/*sender和"#@[]"不同*/

if (qmeox("-owner") == 0)

{

if (qmeox("-owner-default") == 0)

{

if (!stralloc_copys(&ueo,local)) temp_nomem();

if (!stralloc_cats(&ueo,"-owner-@")) temp_nomem();

if (!stralloc_cats(&ueo,host)) temp_nomem();

if (!stralloc_cats(&ueo,"-@[]")) temp_nomem();

}/*ueo为local+"-owner-@"+host+"-@[]"*/

else

{

if (!stralloc_copys(&ueo,local)) temp_nomem();

if (!stralloc_cats(&ueo,"-owner@")) temp_nomem();

if (!stralloc_cats(&ueo,host)) temp_nomem();

}/*ueo为local+"-owner@"+host*/

}

if (!stralloc_0(&ueo)) temp_nomem();

//转发的发送人地址

if (!env_put2("NEWSENDER",ueo.s)) temp_nomem();

if (!stralloc_ready(&cmds,0)) temp_nomem();

cmds.len = 0;

if (fd != -1)

if (slurpclose(fd,&cmds,256) == -1) temp_nomem();

if (!cmds.len)/*假如fd文件中没有内容*/

{

if (!stralloc_copys(&cmds,aliasempty)) temp_nomem();

flagforwardonly = 0;

}

if (!cmds.len (cmds.s[cmds.len - 1] != '\n'))

if (!stralloc_cats(&cmds,"\n")) temp_nomem();

numforward = 0;/*检查有几行的第一个字符不是'#','.','/',''*/

i = 0;/*i为每行的开始位置*/

for (j = 0;j < cmds.len;++j)

if (cmds.s[j] == '\n')

{

switch(cmds.s[i]) { case '#': case '.': case '/': case '': break;

default: ++numforward; }

i = j + 1;

}

recips = (char **) alloc((numforward + 1) * sizeof(char *));

if (!recips) temp_nomem();

numforward = 0;

flag99 = 0;

i = 0;

for (j = 0;j < cmds.len;++j)

if (cmds.s[j] == '\n')

{

cmds.s[j] = 0;

k = j;

while ((k > i) && (cmds.s[k - 1] == ' ') (cmds.s[k - 1] == '\t'))

cmds.s[--k] = 0;

// 字符 传送类型 值

// # 无 (注释) 忽略

// 程序 由shell 执行的命令

// / 或者 . mbox邮箱格式 (假如路径最后一个字符不是一个斜杠) mbox 的路径名 (包括斜杠"/"或者 点".")

// / 或者 . maildir邮箱格式 (假如路径最后一个字符是一个反斜杠) maildir 的路径名 (包括斜杠"/"或者 点".")

// & 转发 转发邮件的地址

// 字母或者数字 转发 转发邮件的地址 (包括第一个字符)

switch(cmds.s[i])

{

case 0: /* k == i */

if (i) break;

strerr_die1x(111,"Uh-oh: first line of .qmail file is blank. (#4.2.1)");

case '#':

break;

case '.':

case '/':

++count_file;

if (flagforwardonly) strerr_die1x(111,"Uh-oh: .qmail has file delivery but has x bit set. (#4.7.0)");

if (cmds.s[k - 1] == '/')

if (flagdoit) maildir(cmds.s + i);///////////////////////////////////////////

else sayit("maildir ",cmds.s + i,k - i);

else

if (flagdoit) mailfile(cmds.s + i);

else sayit("mbox ",cmds.s + i,k - i);

break;

case '':

++count_program;

if (flagforwardonly) strerr_die1x(111,"Uh-oh: .qmail has prog delivery but has x bit set. (#4.7.0)");

if (flagdoit) mailprogram(cmds.s + i + 1);

else sayit("program ",cmds.s + i + 1,k - i - 1);

break;

case '+':

if (str_equal(cmds.s + i + 1,"list"))

flagforwardonly = 1;

break;

case '&':

++i;

default:

++count_forward;

if (flagdoit) recips[numforward++] = cmds.s + i;

else sayit("forward ",cmds.s + i,k - i);

break;

}

i = j + 1;

if (flag99) break;

}

//转发的地址数不为0就转发

if (numforward) if (flagdoit)

{

recips[numforward] = 0;

mailforward(recips);

}

count_print();

_exit(0);

}

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