自学教程：C++ strerr_die2sys函数代码示例

void normal_bottom(char format)/* Copies bottom text and the original message to the new message */{  if (flagbottom) {    copy(&qq,"text/bottom",flagcd);    if (flagcd && format != RFC1153) {      if (flagcd == 'B') {	encodeB("",0,&line,2);	/* flush */	qmail_put(&qq,line.s,line.len);      }      hdr_boundary(0);      hdr_ctype(CTYPE_MESSAGE);      hdr_adds("Content-Disposition: inline; filename=request.msg");      qmail_puts(&qq,"/n");    }    qmail_puts(&qq,"Return-Path: <");    if (!quote2(&quoted,sender)) die_nomem();    qmail_put(&qq,quoted.s,quoted.len);    qmail_puts(&qq,">/n");    if (seek_begin(0) == -1)      strerr_die2sys(111,FATAL,MSG(ERR_SEEK_INPUT));    if (qmail_copy(&qq,&ssin2,copylines) != 0)      strerr_die2sys(111,FATAL,MSG(ERR_READ_INPUT));  } else {    if (flagcd == 'B' && format != RFC1153) {      encodeB("",0,&line,2);	/* flush */      qmail_put(&qq,line.s,line.len);    }  }}

void write_ulong(unsigned long num,unsigned long cum,unsigned long dat,		 const char *fn,const char *fnn)/* write num to "fnn" add ':' & cum if cum <>0, then move "fnn" to "fn" */{  int fd;  fd = open_trunc(fnn);  if (fd == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_CREATE,fnn));  substdio_fdbuf(&ssnum,write,fd,numbuf,sizeof(numbuf));  if (substdio_put(&ssnum,strnum,fmt_ulong(strnum,num)) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));  if (substdio_puts(&ssnum,":") == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));  if (substdio_put(&ssnum,strnum,fmt_ulong(strnum,cum)) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));  if (dat) {    if (substdio_puts(&ssnum,":") == -1)       strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));    if (substdio_put(&ssnum,strnum,fmt_ulong(strnum,dat)) == -1)       strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));  }  if (substdio_puts(&ssnum,"/n") == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnn));  if (substdio_flush(&ssnum) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_FLUSH,fnn));  if (fsync(fd) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_SYNC,fnn));  if (close(fd) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_CLOSE,fnn));  wrap_rename(fnn,fn);}

main(){  char *x;  int udp53;  x = env_get("IP");  if (!x)    strerr_die2x(111,fatal,"$IP not set");  if (!ip4_scan(x,ip))    strerr_die3x(111,fatal,"unable to parse IP address ",x);  udp53 = socket_udp();  if (udp53 == -1)    strerr_die2sys(111,fatal,"unable to create UDP socket: ");  if (socket_bind4_reuse(udp53,ip,53) == -1)    strerr_die2sys(111,fatal,"unable to bind UDP socket: ");  droproot(fatal);  initialize();    ndelay_off(udp53);  socket_tryreservein(udp53,65536);  for (;;) {    len = socket_recv4(udp53,buf,sizeof buf,ip,&port);    if (len < 0) continue;    if (!doit()) continue;    if (response_len > 512) response_tc();    socket_send4(udp53,response,response_len,ip,port);    /* may block for buffer space; if it fails, too bad */  }}

int main(int argc,char **argv,char **envp){  int piin[2];  int piout[2];  pid[fmt_ulong(pid,getpid())] = 0;  if (argc < 2)    strerr_die1x(100,"recordio: usage: recordio program [ arg ... ]");  if (pipe(piin) == -1)    strerr_die2sys(111,FATAL,"unable to create pipe: ");  if (pipe(piout) == -1)    strerr_die2sys(111,FATAL,"unable to create pipe: ");  switch(fork()) {    case -1:      strerr_die2sys(111,FATAL,"unable to fork: ");    case 0:      sig_ignore(sig_pipe);      close(piin[0]);      close(piout[1]);      doit(piin[1],piout[0]);  }  close(piin[1]);  close(piout[0]);  if (fd_move(0,piin[0]) == -1)    strerr_die2sys(111,FATAL,"unable to move descriptors: ");  if (fd_move(1,piout[1]) == -1)    strerr_die2sys(111,FATAL,"unable to move descriptors: ");  pathexec_run(argv[1],argv + 1,envp);  strerr_die4sys(111,FATAL,"unable to run ",argv[1],": ");}

int main(int argc, char **argv, char **envp) {  uint8_t buf[1024];  cdb_t cdb;  char *key;  uint32_t len;  uint32_t r;  uint32_t pos;  uint32_t skip = 0;  char *skip_str;    if (!*argv || !*++argv)    usage();  key = *argv;    skip_str = *++argv;  if (skip_str) {    if (sscanf(skip_str, "%" PRIu32, &skip) != strlen(skip_str))      usage();  }    /* Initialize the cdb struct using stdin as it's file descriptor. */  if (cdb_init(&cdb, 0) == -1)    strerr_die2x(111, FATAL, "failed to initialize cdb");      for (;;) {    r = cdb_find_next(&cdb, key, strlen(key));    if (r == -1)      strerr_die2sys(111, FATAL, "unable to read input: ");    if (!r)      _exit(100);          if (!skip)      break;    skip--;  }    /* If there's a record in the cdb file, then the cdb structs dlen property   * will be set to a non-zero value and it's position will be set to the   * offset in the file containing the data.  Read the data in chunks and send   * it to stdout. */  len = cdb.dlen;  pos = cdb.dpos;  while (len > 0) {    r = sizeof(buf);    if (r > len)      r = len;    if (cdb_read(buf, r, &cdb, pos) == -1)      strerr_die2sys(111, FATAL, "unable to read input: ");    if (bio_put(bio_1, buf, r) == -1)      strerr_die2sys(111, FATAL, "unable to write output: ");    pos += r;    len -= r;  }  if (bio_flush(bio_1) == -1)    strerr_die2sys(111, FATAL, "unable to write output: ");      cdb_free(&cdb);    return 0;}

void copybottom(int forcebottom){  if (!omitbottom || forcebottom) {    copy(&qq,"text/bottom",flagcd);    if (flagcd) {      if (flagcd == 'B') {	encodeB("",0,&line,2);	/* flush */	qmail_put(&qq,line.s,line.len);      }      hdr_boundary(0);      hdr_ctype(CTYPE_MESSAGE);      hdr_adds("Content-Disposition: inline; filename=request.msg");      qmail_puts(&qq,"/n");    }    qmail_puts(&qq,"Return-Path: <");    quote2(&quoted,sender);    qmail_put(&qq,quoted.s,quoted.len);    qmail_puts(&qq,">/n");    if (seek_begin(0) == -1)      strerr_die2sys(111,FATAL,MSG(ERR_SEEK_INPUT));    if (qmail_copy(&qq,&ssin2,copylines) != 0)      strerr_die2sys(111,FATAL,MSG(ERR_READ_INPUT));    if (flagcd)      hdr_boundary(1);  } else {    if (flagcd == 'B') {      encodeB("",0,&line,2);	/* flush even if no bottom */      qmail_put(&qq,line.s,line.len);    }  }  qmail_from(&qq,from.s);}

int main(int argc,const char *const *argv,const char *const *envp){  struct passwd *pw;  const char *account;  char strnum[FMT_ULONG];  account = *++argv;  if (!account || !*++argv)    usage();  pw = getpwnam(account);  if (!pw)    strerr_die3x(111,FATAL,"unknown account ",account);  if (!pathexec_env("HOME",pw->pw_dir)) nomem();  if (!pathexec_env("SHELL",pw->pw_shell)) nomem();  if (!pathexec_env("USER",pw->pw_name)) nomem();  strnum[fmt_ulong(strnum,pw->pw_gid)] = 0;  if (!pathexec_env("GID",strnum)) nomem();  strnum[fmt_ulong(strnum,pw->pw_uid)] = 0;  if (!pathexec_env("UID",strnum)) nomem();  if (chdir(pw->pw_dir) != 0)    strerr_die3sys(111,FATAL,"unable to chdir to ", pw->pw_dir);  if (prot_gid(pw->pw_gid) == -1)    strerr_die2sys(111,FATAL,"unable to setgid");  if (prot_gids(pw->pw_name, pw->pw_gid) == -1)    strerr_die2sys(111,FATAL,"unable to initgroups");  if (prot_uid(pw->pw_uid) == -1)    strerr_die2sys(111,FATAL,"unable to setuid");  pathexec_run(*argv,argv,envp);  strerr_die3sys(111,FATAL,"unable to run ",*argv);}

void didentd_init(){  char *x;  unsigned long id;  x = env_get("ROOT");  if (!x)     strerr_die2x(111,FATAL,"$ROOT not set");  if (chdir(x) == -1)    strerr_die4sys(111,FATAL,"unable to chdir to ",x,": ");  x = env_get("GID");  if (!x)    strerr_die2x(111,FATAL,"$GID not set");  scan_ulong(x,&id);  if (prot_gid((int) id) == -1)    strerr_die2sys(111,FATAL,"unable to setgid: ");  x = env_get("UID");  if (!x)    strerr_die2x(111,FATAL,"$UID not set");  scan_ulong(x,&id);  if (prot_uid((int) id) == -1)    strerr_die2sys(111,FATAL,"unable to setuid: ");}

void didentd_init(){  /* chroot() to /proc/net/ and switch to $UID:$GID */  char *x;  unsigned long id;  if (chdir("/proc/net/") == -1)    strerr_die2sys(111,FATAL,"unable to chdir to '/proc/net/': ");  if (chroot(".") == -1)    strerr_die2sys(111,FATAL,"unable to chdir to '/proc/net/': ");  x = env_get("GID");  if (!x)    strerr_die2x(111,FATAL,"$GID not set");  scan_ulong(x,&id);  if (prot_gid((int) id) == -1)    strerr_die2sys(111,FATAL,"unable to setgid: ");  x = env_get("UID");  if (!x)    strerr_die2x(111,FATAL,"$UID not set");  scan_ulong(x,&id);  if (prot_uid((int) id) == -1)    strerr_die2sys(111,FATAL,"unable to setuid: ");}

static void do_get(const char *action){  unsigned long u;  struct stat st;  char ch;  int r;  unsigned int pos;  int fd;  if (!flagget)    strerr_die2x(100,FATAL,MSG(ERR_NOT_AVAILABLE));  hdr_subject(MSG(SUB_GET_MSG));  hdr_ctboundary();  copy(&qq,"text/top",flagcd);  pos = str_len(ACTION_GET);  if (!case_starts(action,ACTION_GET))    pos = str_len(ALT_GET);  if (action[pos] == '.' || action [pos] == '_') pos++;  scan_ulong(action + pos,&u);  stralloc_copys(&line,"archive/");  stralloc_catb(&line,strnum,fmt_ulong(strnum,u / 100));  stralloc_cats(&line,"/");  stralloc_catb(&line,strnum,fmt_uint0(strnum,(unsigned int) (u % 100),2));  stralloc_0(&line);  fd = open_read(line.s);  if (fd == -1)    if (errno != error_noent)      strerr_die2sys(111,FATAL,MSG1(ERR_OPEN,line.s));    else      copy_act("text/get-bad");  else {    if (fstat(fd,&st) == -1)      copy_act("text/get-bad");    else if (!(st.st_mode & 0100))      copy_act("text/get-bad");    else {      showsend("get");      substdio_fdbuf(&sstext,read,fd,textbuf,sizeof(textbuf));      qmail_puts(&qq,"> ");      for (;;) {	r = substdio_get(&sstext,&ch,1);	if (r == -1) strerr_die2sys(111,FATAL,MSG1(ERR_READ,line.s));	if (r == 0) break;	qmail_put(&qq,&ch,1);	if (ch == '/n') qmail_puts(&qq,"> ");      }      qmail_puts(&qq,"/n");    }    close(fd);  }  copybottom(0);  qmail_to(&qq,target.s);}

void f_close(void){  if (substdio_flush(&ss) == -1)    strerr_die2sys(111,FATAL,MSG1(ERR_FLUSH,dirplus.s));  if (fsync(ss.fd) == -1)    strerr_die2sys(111,FATAL,MSG1(ERR_SYNC,dirplus.s));  if (close(ss.fd) == -1) /* NFS stupidity */    strerr_die2sys(111,FATAL,MSG1(ERR_CLOSE,dirplus.s));  keyaddtime();}

void close_proper(substdio *ss,const char *s,const char *sn)/* flush,sync,close,move sn->s) */{   if (substdio_flush(ss) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_FLUSH,s));  if (flagsync)    if (fsync(ss->fd) == -1)       strerr_die2sys(111,FATAL,MSG1(ERR_SYNC,s));  if (close(ss->fd) == -1)     strerr_die2sys(111,FATAL,MSG1(ERR_CLOSE,s));  wrap_rename(sn,s);}

/*void show(const char *desc, stralloc *s){  buffer_puts(buffer_2,desc);  buffer_puthex(buffer_2,s->s,s->len);  buffer_putsflush(buffer_2,"/n");}*/int main(int argc, char * argv[]){    int r;    const char* pk0;    const char* sk0;    /* Check args */    pk0 = ((argc<2) ? env_get("NACL_PUBLICKEY_FILE") : argv[1]);    sk0 = ((argc<3) ? env_get("NACL_SECRETKEY_FILE") : argv[2]);    if(pk0==0 || sk0==0)        strerr_die1x(100,"crypto-box: usage: crypto-box [ publickeyfile ] [ secretkeyfile ]");    /* Read public key */    if(openreadclose(argv[1],&pk,crypto_box_PUBLICKEYBYTES)<=0)        strerr_die2sys(111,FATAL,"unable to read public key: ");    /* Read secret key */    if(openreadclose(argv[2],&sk,crypto_box_SECRETKEYBYTES)<=0)        strerr_die2sys(111,FATAL,"unable to read secret key: ");    /* Create shared key */    if(crypto_str_box_beforenm(&k,&pk,&sk))        strerr_die2x(111,FATAL,"failed to create shared-key");    /* Decrypt each chunk */    for (;;) {        /* Read nonce */        if((r=netstring_read(buffer_0,&n))!=0)            strerr_die2x(111,FATAL,"failed to read nonce");        if(n.len==0) break;        if(n.len!=crypto_box_NONCEBYTES)            strerr_die2x(111,FATAL,"nonce was incorrect size");        /* Read cipher */        if(netstring_read(buffer_0,&c)!=0)            strerr_die2x(111,FATAL,"failed to read cipher");        /* Decrypt message */        if(crypto_str_box_open_afternm(&m,&c,&n,&k)!=0)            strerr_die2x(111,FATAL,"decryption failed");        /* Write message */        if(buffer_put(buffer_1,m.s,m.len)!=0)            strerr_die2sys(111,FATAL,"failed to output message: ");    }    buffer_flush(buffer_1);    return 0;}

const char *get_from(const char *adr, /* target address */		     const char *act) /* action *//* If we captured a from line, it will be from the subscriber, except   *//* when -S is used when it's usually from the subscriber, but of course *//* could be from anyone. The matching to stored data is required only   *//* to support moderated lists, and in cases where a new -sc is issued   *//* because an old one was invalid. In this case, we read through the    *//* from file trying to match up a timestamp with that starting in       *//* *(act+3). If the time stamp matches, we compare the target address   *//* itself. act + 3 must be a legal part of the string returns pointer to*//* fromline, NULL if not found. Since the execution time from when to   *//* storage may differ, we can't assume that the timestamps are in order.*/{  int fd;  const char *fl;  unsigned int pos;  unsigned long thistime;  unsigned long linetime;  if (!flagstorefrom) return 0;  if (fromline.len) {	/* easy! We got it in this message */    stralloc_0(&fromline);    return fromline.s;  }			/* need to recover it from DIR/from */  fl = 0;  (void) scan_ulong(act+3,&thistime);  if ((fd = open_read("from")) == -1) {    if (errno == error_noent)      return 0;    else      strerr_die2sys(111,FATAL,MSG1(ERR_READ,"from"));  }  substdio_fdbuf(&sstext,read,fd,textbuf,(int) sizeof(textbuf));  for (;;) {    if (getln(&sstext,&fromline,&match,'/n') == -1)      strerr_die2sys(111,FATAL,MSG1(ERR_READ,"from"));    if (!match) break;    fromline.s[fromline.len - 1] = (char) 0;	/* now:time addr/0fromline/0 read all. They can be out of order! */    pos = scan_ulong(fromline.s,&linetime);    if (linetime != thistime) continue;    if (!str_diff(fromline.s + pos + 1,adr)) {      pos = str_len(fromline.s);      if (pos < fromline.len) {	fl = fromline.s + pos + 1;	break;      }    }  }  close(fd);  return fl;}

void linkdotdir(const char *dash,const char *slash){  stralloc_copy(&dotplus,&dot);  stralloc_cats(&dotplus,dash);  stralloc_0(&dotplus);  dirplusmake(slash);  if (flags['e' - 'a'])    if (unlink(dotplus.s) == -1)      if (errno != error_noent)        strerr_die2sys(111,FATAL,MSG1(ERR_DELETE,dotplus.s));  if (symlink(dirplus.s,dotplus.s) == -1)    strerr_die2sys(111,FATAL,MSG1(ERR_CREATE,dotplus.s));  keyaddtime();}

main(){  int pid;  int wstat;  char ch;  sig_ignore(sig_pipe);  pid = fork();  if (pid == -1) strerr_die2sys(111,"mconnect-io: fatal: ","unable to fork: ");  if (!pid) {    buffer_init(&bin,myread,0,inbuf,sizeof inbuf);    buffer_init(&bout,write,7,outbuf,sizeof outbuf);    while (buffer_get(&bin,&ch,1) == 1) {      if (ch == '/n') buffer_put(&bout,"/r",1);      buffer_put(&bout,&ch,1);    }    _exit(0);  }  buffer_init(&bin,myread,6,inbuf,sizeof inbuf);  buffer_init(&bout,write,1,outbuf,sizeof outbuf);  while (buffer_get(&bin,&ch,1) == 1)    buffer_put(&bout,&ch,1);  kill(pid,sig_term);  wait_pid(&wstat,pid);  _exit(0);}

void f_init(char **script){  int i;  int fd;  for (i = 0;script[i];++i)    ;  f = (int *) alloc(i * sizeof(*f));  if (!f) strerr_die2x(111,FATAL,"out of memory");  for (i = 0;script[i];++i) {    fd = -1;    if (script[i][0] == '=') {      if (fchdir(fdstartdir) == -1)        strerr_die2sys(111,FATAL,"unable to switch to starting directory: ");      fd = open_append(script[i] + 1);      if (fd == -1)        strerr_die4sys(111,FATAL,"unable to create ",script[i] + 1,": ");      close(fd);      fd = open_write(script[i] + 1);      if (fd == -1)        strerr_die4sys(111,FATAL,"unable to write ",script[i] + 1,": ");      coe(fd);    }    f[i] = fd;  }}

void get(stralloc *sa){  int match;  if (getln(subfdin,sa,&match,'/n') == -1)    strerr_die2sys(111,FATAL,MSG(ERR_READ_INPUT));  if (!match) _exit(0);}

void frm(const char *slash){  dirplusmake(slash);  if (unlink(dirplus.s) == -1)    if (errno != error_noent)    strerr_die2sys(111,FATAL,MSG1(ERR_DELETE,dirplus.s));}

static int execute_line(const char *fn,const char *line){  int child;  int code;  if (seek_begin(0) == -1)    strerr_die2sys(111,FATAL,MSG(ERR_SEEK_INPUT));  while (*line	 && (*line == '/t'	     || *line == ' '))      ++line;  switch (*line) {  case '#':    /* ignore comments */    return 0;  case '|':    if ((child = wrap_fork()) == 0)      wrap_execsh(line+1);    code = wrap_waitpid(child);    ++did_program;    return code;  case '/':  case '.':    strerr_die5x(100,FATAL,basedir.s,"/",fn,": Delivery to files is not supported.");    return 100;  default:    if (*line == '&')      ++line;    forward(line);    return 0;  }}

static void flushit(int fd){  if (fd > 0)    if (substdio_flush(&ssarchive) == -1	|| fchmod(fd,MODE_ARCHIVE|0700) == -1	|| close(fd) == -1)      strerr_die2sys(111,FATAL,MSG1(ERR_WRITE,fnaf.s));}

int wrap_stat(const char *fn,struct stat *st){  int r;  if ((r = stat(fn,st)) == -1      && errno != error_noent)    strerr_die2sys(111,FATAL,MSG1(ERR_STAT,fn));  return r;}

void dcreate(const char *slash){  dirplusmake(slash);  if (mkdir(dirplus.s,0755) == -1)    if ((errno != error_exist) || !flags['e' - 'a'])      strerr_die2sys(111,FATAL,MSG1(ERR_CREATE,dirplus.s));  keyaddtime();}

static int open_template(stralloc *fn){  int fd;  struct stat st;  stralloc_0(fn);  if (stat(fn->s,&st) == -1)    strerr_die2sys(111,FATAL,MSG1(ERR_STAT,fn->s));  if (S_ISDIR(st.st_mode)) {    --fn->len;    stralloc_cats(fn,TXT_EZMLMRC);    stralloc_0(fn);  }  if ((fd = open_read(fn->s)) == -1) {    if (errno != error_noent)      strerr_die2sys(111,FATAL,MSG1(ERR_OPEN,fn->s));    else      strerr_die3x(100,FATAL,template.s,MSG(ERR_NOEXIST));

int main(int argc,const char *const *argv,const char *const *envp){  account = *++argv;  if (!account || !*++argv)    strerr_die1x(100,"setuidgid: usage: setuidgid account child");  pw = getpwnam(account);  if (!pw)    strerr_die3x(111,FATAL,"unknown account ",account);  if (prot_gid(pw->pw_gid) == -1)    strerr_die2sys(111,FATAL,"unable to setgid: ");  if (prot_uid(pw->pw_uid) == -1)    strerr_die2sys(111,FATAL,"unable to setuid: ");  pathexec_run(*argv,argv,envp);  strerr_die4sys(111,FATAL,"unable to run ",*argv,": ");}

void read_passwd(void) {  if (!password.len) {    buffer_init(&b,buffer_unixread,3,bspace,sizeof bspace);    if (getln(&b,&password,&match,'/0') == -1)      strerr_die2sys(111,FATAL,"unable to read password: ");    close(3);    if (match) --password.len;  }}

void defaultsoa_init(int fd){  struct stat st;  if (fstat(fd,&st) == -1)    strerr_die2sys(111,FATAL,"unable to stat data: ");  uint32_pack_big(defaultsoa,st.st_mtime);  if (byte_equal(defaultsoa,4,"/0/0/0/0"))    defaultsoa[3] = 1;  byte_copy(defaultsoa + 4,16,"/0/0/100/000/0/0/010/000/0/020/000/000/0/0/012/000");}

int exists(const char *dpm){  struct stat st;  dirplusmake(dpm);  if (stat(dirplus.s,&st) == -1) {    if (errno == error_noent)      return 0;    strerr_die2sys(111,FATAL,MSG1(ERR_STAT,dirplus.s));  }  return 1;}

void doit(int resource,const char *arg){  unsigned long u;  struct rlimit r;  if (getrlimit(resource,&r) == -1)    strerr_die2sys(111,FATAL,"getrlimit failed: ");  if (str_equal(arg,"="))    r.rlim_cur = r.rlim_max;  else {    if (arg[scan_ulong(arg,&u)]) die_usage();    r.rlim_cur = u;    if (r.rlim_cur > r.rlim_max)      r.rlim_cur = r.rlim_max;  }  if (setrlimit(resource,&r) == -1)    strerr_die2sys(111,FATAL,"setrlimit failed: ");}