自学教程：C++ xsetenv函数代码示例

void set_global_stop_on_not_reportable(bool enabled, int flags/*unused - persistent*/){    assert_global_configuration_initialized();    if (enabled)        xsetenv(STOP_ON_NOT_REPORTABLE, "1");    else        xsetenv(STOP_ON_NOT_REPORTABLE, "0");}

static void euidgid(char *user){	struct bb_uidgid_t ugid;	if (!get_uidgid(&ugid, user, 1)) {		bb_error_msg_and_die("unknown user/group: %s", user);	}	xsetenv("GID", utoa(ugid.gid));	xsetenv("UID", utoa(ugid.uid));}

/* Setting munin specific vars */static void setenvvars_system() {	/* Some locales use "," as decimal separator.	 * This can mess up a lot of plugins. */	xsetenv("LC_ALL", "C", yes);	/* LC_ALL should be enough, but some plugins don't	 * follow specs (#1014) */	xsetenv("LANG", "C", yes);	/* PATH should be *very* sane by default. Can be	 * overrided via config file if needed	 * (Closes #863 and #1128).  */	xsetenv("PATH", "/usr/sbin:/usr/bin:/sbin:/bin", yes);}

static void change_user(const struct passwd *pas){	xsetenv("USER", pas->pw_name);	xsetenv("HOME", pas->pw_dir);	xsetenv("SHELL", DEFAULT_SHELL);	/* initgroups, setgid, setuid */	change_identity(pas);	if (chdir(pas->pw_dir) < 0) {		bb_perror_msg("chdir(%s) by %s failed",				pas->pw_dir, pas->pw_name);		xchdir("/tmp");	}}

// main takes care of OS-specific startup and dispatches to xmain.voidmain(int argc, char **argv){	Buf b;	setvbuf(stdout, nil, _IOLBF, BUFSIZ);	setvbuf(stderr, nil, _IOLBF, BUFSIZ);	binit(&b);	rfork(RFENVG);	slash = "/";	gohostos = "plan9";	xgetenv(&b, "objtype");	if(b.len == 0)		fatal("$objtype is unset");	gohostarch = btake(&b);	xgetenv(&b, "GOBIN");	if(b.len == 0){		bpathf(&b, "/%s/bin", gohostarch);		xsetenv("GOBIN", bstr(&b));	}	srand(time(0)+getpid());	init();	xmain(argc, argv);	bfree(&b);	exits(nil);}

/** * Run a script. * argv[0]:intf argv[1]:script_name argv[2]:junk argv[3]:NULL */static int run(char *argv[3], const char *param, struct in_addr *ip){	int status;	char *addr = addr; /* for gcc */	const char *fmt = "%s %s %s" + 3;	argv[2] = (char*)param;	VDBG("%s run %s %s/n", argv[0], argv[1], argv[2]);	if (ip) {		addr = inet_ntoa(*ip);		xsetenv("ip", addr);		fmt -= 3;	}	if (verbose)		bb_info_msg(fmt, argv[2], argv[0], addr);	status = spawn_and_wait(argv + 1);	if (status < 0) {		bb_perror_msg("%s %s %s" + 3, argv[2], argv[0]);		return -errno;	}	if (status != 0)		bb_error_msg("script %s %s failed, exitcode=%d", argv[1], argv[2], status & 0xff);	return status;}

/* TODO: use recursive_action? */static NOINLINE void edir(const char *directory_name){	int wdir;	DIR *dir;	struct dirent *d;	int fd;	wdir = xopen(".", O_RDONLY | O_NDELAY);	xchdir(directory_name);	dir = xopendir(".");	for (;;) {		char buf[256];		char *tail;		int size;		errno = 0;		d = readdir(dir);		if (!d) {			if (errno)				bb_perror_msg_and_die("readdir %s",						directory_name);			break;		}		if (d->d_name[0] == '.')			continue;		fd = open(d->d_name, O_RDONLY | O_NDELAY);		if (fd < 0) {			if ((errno == EISDIR) && directory_name) {				if (option_mask32 & OPT_v)					bb_perror_msg("warning: %s/%s is a directory",						directory_name, d->d_name);				continue;			}			bb_perror_msg_and_die("open %s/%s",						directory_name, d->d_name);		}		size = full_read(fd, buf, sizeof(buf)-1);		close(fd);		if (size < 0)			bb_perror_msg_and_die("read %s/%s",					directory_name, d->d_name);		if (size == 0) {			unsetenv(d->d_name);			continue;		}		buf[size] = '/n';		tail = strchr(buf, '/n');		/* skip trailing whitespace */		while (1) {			*tail = '/0';			tail--;			if (tail < buf || !isspace(*tail))				break;		}		xsetenv(d->d_name, buf);	}	closedir(dir);	xfchdir(wdir);	close(wdir);}

static void set_env_vars(struct passwd *pas, const char *shell){	/* POSIX requires crond to set up at least HOME, LOGNAME, PATH, SHELL.	 * We assume crond inherited suitable PATH.	 */#if SETENV_LEAKS	safe_setenv(&G.env_var_logname, "LOGNAME", pas->pw_name);	safe_setenv(&G.env_var_user, "USER", pas->pw_name);	safe_setenv(&G.env_var_home, "HOME", pas->pw_dir);	safe_setenv(&G.env_var_shell, "SHELL", shell);#else	xsetenv("LOGNAME", pas->pw_name);	xsetenv("USER", pas->pw_name);	xsetenv("HOME", pas->pw_dir);	xsetenv("SHELL", shell);#endif}

/* Setting munin specific vars */static void setenvvars_munin() {	/* munin-node will override this with the IP of the	 * connecting master */	if (client_ip != NULL && client_ip[0] != '/0') {		xsetenv("MUNIN_MASTER_IP", client_ip, no);	}	/* Tell plugins about supported capabilities */	xsetenv("MUNIN_CAP_MULTIGRAPH", "1", no);	/* We only have one user, so using a fixed path */	xsetenv("MUNIN_PLUGSTATE", "/var/tmp", no);	xsetenv("MUNIN_STATEFILE", "/dev/null", no);	/* That's where plugins should live */	xsetenv("MUNIN_LIBDIR", "/usr/share/munin", no);}

void set_global_create_private_ticket(bool enabled, int flags/*unused - persistent*/){    assert_global_configuration_initialized();    if (enabled)        xsetenv(CREATE_PRIVATE_TICKET, "1");    else        safe_unsetenv(CREATE_PRIVATE_TICKET);}

void setup_environment ( const char *shell, int loginshell, int changeenv, const struct passwd *pw ){	if ( loginshell ) {		const char *term;		/* Change the current working directory to be the home directory		 * of the user.  It is a fatal error for this process to be unable		 * to change to that directory.  There is no "default" home		 * directory.		 * Some systems default to HOME=/		 */		if ( chdir ( pw-> pw_dir )) {			if ( chdir ( "/" )) {				syslog ( LOG_WARNING, "unable to cd to %s' for user %s'/n", pw-> pw_dir, pw-> pw_name );				bb_error_msg_and_die ( "cannot cd to home directory or /" );			}			fputs ( "warning: cannot change to home directory/n", stderr );		}		/* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.		   Unset all other environment variables.  */		term = getenv ("TERM");		clearenv ( );		if ( term )			xsetenv ( "TERM", term );		xsetenv ( "HOME",    pw-> pw_dir );		xsetenv ( "SHELL",   shell );		xsetenv ( "USER",    pw-> pw_name );		xsetenv ( "LOGNAME", pw-> pw_name );		xsetenv ( "PATH",    ( pw-> pw_uid ? DEFAULT_LOGIN_PATH : DEFAULT_ROOT_LOGIN_PATH ));	}	else if ( changeenv ) {		/* Set HOME, SHELL, and if not becoming a super-user,		   USER and LOGNAME.  */		xsetenv ( "HOME",  pw-> pw_dir );		xsetenv ( "SHELL", shell );		if  ( pw-> pw_uid ) {			xsetenv ( "USER",    pw-> pw_name );			xsetenv ( "LOGNAME", pw-> pw_name );		}	}}

/* Restore CLASSPATH to its previous value.  */voidreset_classpath (char *old_classpath){  if (old_classpath != NULL)    {      xsetenv (CLASSPATHVAR, old_classpath, 1);      free (old_classpath);    }  else    unsetenv (CLASSPATHVAR);}

static void run_login_script(struct passwd *pw, char *full_tty){    char *t_argv[2];    t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");    if (t_argv[0]) {        t_argv[1] = NULL;        xsetenv("LOGIN_TTY", full_tty);        xsetenv("LOGIN_USER", pw->pw_name);        xsetenv("LOGIN_UID", utoa(pw->pw_uid));        xsetenv("LOGIN_GID", utoa(pw->pw_gid));        xsetenv("LOGIN_SHELL", pw->pw_shell);        spawn_and_wait(t_argv);	/* NOMMU-friendly */        unsetenv("LOGIN_TTY");        unsetenv("LOGIN_USER");        unsetenv("LOGIN_UID");        unsetenv("LOGIN_GID");        unsetenv("LOGIN_SHELL");    }}

intmain (int argc, char *argv[]){  char *s;  int result = 0;  /* Clean up environment.  */  unsetenv ("LANGUAGE");  unsetenv ("LC_ALL");  unsetenv ("LC_MESSAGES");  unsetenv ("LC_CTYPE");  unsetenv ("LANG");  unsetenv ("OUTPUT_CHARSET");  xsetenv ("LC_ALL", argv[1], 1);  setlocale (LC_ALL, "");  textdomain ("codeset");  bindtextdomain ("codeset", "gt-4");  /* Here we expect output in ISO-8859-1.     Except on Darwin 7 or newer and on BeOS, for which locale_charset ()     always returns "UTF-8" (see config.charset).  */#if !((defined __APPLE__ && defined __MACH__) || defined __BEOS__)  s = gettext ("cheese");  if (strcmp (s, "K/344se"))    {      fprintf (stderr, "call 1 returned: %s/n", s);      result = 1;    }#endif  bind_textdomain_codeset ("codeset", "UTF-8");  /* Here we expect output in UTF-8.  */  s = gettext ("cheese");  if (strcmp (s, "K/303/244se"))    {      fprintf (stderr, "call 2 returned: %s/n", s);      result = 1;    }  bind_textdomain_codeset ("codeset", "ISO-8859-1");  /* Here we expect output in ISO-8859-1.  */  s = gettext ("cheese");  if (strcmp (s, "K/344se"))    {      fprintf (stderr, "call 3 returned: %s/n", s);      result = 1;    }  return result;}

static voidmodify_environment (const struct passwd *pw, const char *shell){  if (simulate_login)    {      /* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.         Unset all other environment variables.  */      char *term = getenv ("TERM");      if (term)	term = xstrdup (term);      environ = xmalloc ((6 + !!term) * sizeof (char *));      environ[0] = NULL;      if (term) {	xsetenv ("TERM", term, 1);	free(term);      }      xsetenv ("HOME", pw->pw_dir, 1);      if (shell)	xsetenv ("SHELL", shell, 1);      xsetenv ("USER", pw->pw_name, 1);      xsetenv ("LOGNAME", pw->pw_name, 1);      set_path(pw);    }  else    {      /* Set HOME, SHELL, and (if not becoming a superuser)	 USER and LOGNAME.  */      if (change_environment)        {          xsetenv ("HOME", pw->pw_dir, 1);	  if (shell)            xsetenv ("SHELL", shell, 1);	  if (getlogindefs_bool ("ALWAYS_SET_PATH", 0))	    set_path(pw);          if (pw->pw_uid)            {              xsetenv ("USER", pw->pw_name, 1);              xsetenv ("LOGNAME", pw->pw_name, 1);            }        }    }  export_pamenv ();}

// The bootstrap command runs a build from scratch,// stopping at having installed the go_bootstrap command.voidcmdbootstrap(int argc, char **argv){	int i;	Buf b;	char *oldgoos, *oldgoarch, *oldgochar;	binit(&b);	ARGBEGIN{	case 'a':		rebuildall = 1;		break;	case 'v':		vflag++;		break;	default:		usage();	}ARGEND	if(argc > 0)		usage();	if(rebuildall)		clean();	goversion = findgoversion();	setup();	xsetenv("GOROOT", goroot);	xsetenv("GOROOT_FINAL", goroot_final);	// For the main bootstrap, building for host os/arch.	oldgoos = goos;	oldgoarch = goarch;	oldgochar = gochar;	goos = gohostos;	goarch = gohostarch;	gochar = gohostchar;	xsetenv("GOARCH", goarch);	xsetenv("GOOS", goos);	for(i=0; i<nelem(buildorder); i++) {		install(bprintf(&b, buildorder[i], gohostchar));		if(!streq(oldgochar, gohostchar) && xstrstr(buildorder[i], "%s"))			install(bprintf(&b, buildorder[i], oldgochar));	}	goos = oldgoos;	goarch = oldgoarch;	gochar = oldgochar;	xsetenv("GOARCH", goarch);	xsetenv("GOOS", goos);	// Build pkg/runtime for actual goos/goarch too.	if(!streq(goos, gohostos) || !streq(goarch, gohostarch))		install("pkg/runtime");	bfree(&b);}

intmain (int argc, char *argv[]){  int n = atoi (argv[2]);  xsetenv ("LC_ALL", argv[1], 1);  if (setlocale (LC_ALL, "") == NULL)    return 1;  textdomain ("cake");  bindtextdomain ("cake", "plural-1-dir");  printf (ngettext ("a piece of cake", "%d pieces of cake", n), n);  printf ("/n");  return 0;}

void make_run_event_state_forwarding(struct run_event_state *state){    /* reset callbacks, just to be sure */    state->alert_callback = run_event_stdio_alert;    state->ask_callback = run_event_stdio_ask;    state->ask_yes_no_callback = run_event_stdio_ask_yes_no;    state->ask_yes_no_yesforever_callback= run_event_stdio_ask_yes_no_yesforever;    state->ask_password_callback = run_event_stdio_ask_password;    /*     * Not sure if we should reset even logging_callback and error_callback?     */    xsetenv("REPORT_CLIENT_SLAVE", "1");}

intmain (int argc, char *argv[]){  int n = 5;  const char *en;  const char *s;  const char *expected_translation;  const char *expected_result;  char buf[100];  xsetenv ("LC_ALL", argv[1], 1);  if (setlocale (LC_ALL, "") == NULL)    {      fprintf (stderr, "Couldn't set locale./n");      exit (1);    }  textdomain ("fc5");  bindtextdomain ("fc5", ".");  s = gettext ("father of %d children");  en = "father of %d children";#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2)  expected_translation = "Vater von %Id Kindern";  expected_result = "Vater von /xdb/xb5 Kindern";#else  expected_translation = "Vater von %d Kindern";  expected_result = "Vater von 5 Kindern";#endif  if (strcmp (s, en) == 0)    {      fprintf (stderr, "String untranslated./n");      exit (1);    }  if (strcmp (s, expected_translation) != 0)    {      fprintf (stderr, "String incorrectly translated./n");      exit (1);    }  sprintf (buf, s, n);  if (strcmp (buf, expected_result) != 0)    {      fprintf (stderr, "printf of translation wrong./n");      exit (1);    }  return 0;}

/* Set CLASSPATH and returns a safe copy of its old value.  */char *set_classpath (const char * const *classpaths, unsigned int classpaths_count,	       bool use_minimal_classpath, bool verbose){  const char *old_CLASSPATH = getenv (CLASSPATHVAR);  char *result = (old_CLASSPATH != NULL ? xstrdup (old_CLASSPATH) : NULL);  char *new_CLASSPATH =    new_classpath (classpaths, classpaths_count, use_minimal_classpath);  if (verbose)    printf (CLASSPATHVAR "=%s ", new_CLASSPATH);  xsetenv (CLASSPATHVAR, new_CLASSPATH, 1);  free (new_CLASSPATH);  return result;}

intmain (int argc, char *argv[]){  unsigned char n = 5;  const char *s;  const char *c1;  const char *c2;  char buf[100];  xsetenv ("LC_ALL", argv[1], 1);  if (setlocale (LC_ALL, "") == NULL)    {      fprintf (stderr, "Couldn't set locale./n");      exit (1);    }  textdomain ("fc4");  bindtextdomain ("fc4", ".");  s = ngettext ("father of %"PRId8" child", "father of %"PRId8" children", n);  c1 = "Vater von %"; c2 = " Kindern";  if (!(strlen (s) > strlen (c1) + strlen (c2)	&& memcmp (s, c1, strlen (c1)) == 0	&& memcmp (s + strlen (s) - strlen (c2), c2, strlen (c2)) == 0))    {      fprintf (stderr, "String not translated./n");      exit (1);    }  if (strchr (s, '<') != NULL || strchr (s, '>') != NULL)    {      fprintf (stderr, "Translation contains <...> markers./n");      exit (1);    }  sprintf (buf, s, n);  if (strcmp (buf, "Vater von 5 Kindern") != 0)    {      fprintf (stderr, "printf of translation wrong./n");      exit (1);    }  return 0;}

/* * Initialize $TERM, $HOME, ... */static void init_environ(struct login_context *cxt){	struct passwd *pwd = cxt->pwd;	char *termenv, **env;	char tmp[PATH_MAX];	int len, i;	termenv = getenv("TERM");	if (termenv)		termenv = xstrdup(termenv);	/* destroy environment unless user has requested preservation (-p) */	if (!cxt->keep_env) {		environ = xmalloc(sizeof(char *));		memset(environ, 0, sizeof(char *));	}	xsetenv("HOME", pwd->pw_dir, 0);	/* legal to override */	xsetenv("USER", pwd->pw_name, 1);	xsetenv("SHELL", pwd->pw_shell, 1);	xsetenv("TERM", termenv ? termenv : "dumb", 1);	free(termenv);	if (pwd->pw_uid) {		if (logindefs_setenv("PATH", "ENV_PATH", _PATH_DEFPATH) != 0)			err(EXIT_FAILURE, _("failed to set the %s environment variable"), "PATH");	} else if (logindefs_setenv("PATH", "ENV_ROOTPATH", NULL) != 0 &&		   logindefs_setenv("PATH", "ENV_SUPATH", _PATH_DEFPATH_ROOT) != 0) {			err(EXIT_FAILURE, _("failed to set the %s environment variable"), "PATH");	}	/* mailx will give a funny error msg if you forget this one */	len = snprintf(tmp, sizeof(tmp), "%s/%s", _PATH_MAILDIR, pwd->pw_name);	if (len > 0 && (size_t) len < sizeof(tmp))		xsetenv("MAIL", tmp, 0);	/* LOGNAME is not documented in login(1) but HP-UX 6.5 does it. We'll	 * not allow modifying it.	 */	xsetenv("LOGNAME", pwd->pw_name, 1);	env = pam_getenvlist(cxt->pamh);	for (i = 0; env && env[i]; i++)		putenv(env[i]);}

void FAST_FUNC setup_environment(const char *shell, int flags, const struct passwd *pw){	if (!shell || !shell[0])		shell = DEFAULT_SHELL;	/* Change the current working directory to be the home directory	 * of the user */	if (!(flags & SETUP_ENV_NO_CHDIR)) {		if (chdir(pw->pw_dir) != 0) {			bb_error_msg("can't change directory to '%s'", pw->pw_dir);			xchdir((flags & SETUP_ENV_TO_TMP) ? "/tmp" : "/");		}	}	if (flags & SETUP_ENV_CLEARENV) {		const char *term;		/* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH.		 * Unset all other environment variables.  */		term = getenv("TERM");		clearenv();		if (term)			xsetenv("TERM", term);		xsetenv("PATH", (pw->pw_uid ? bb_default_path : bb_default_root_path));		goto shortcut;		// No, gcc (4.2.1) is not clever enougn to do it itself.		//xsetenv("USER",    pw->pw_name);		//xsetenv("LOGNAME", pw->pw_name);		//xsetenv("HOME",    pw->pw_dir);		//xsetenv("SHELL",   shell);	} else if (flags & SETUP_ENV_CHANGEENV) {#if ENABLE_PLATFORM_MINGW32#define xsetenv(k, v) xsetenv_if_unset(k, v)#endif		/* Set HOME, SHELL, and if not becoming a super-user,		 * USER and LOGNAME.  */		if (pw->pw_uid) { shortcut:			xsetenv("USER",    pw->pw_name);			xsetenv("LOGNAME", pw->pw_name);		}		xsetenv("HOME",    pw->pw_dir);		xsetenv("SHELL",   shell);	}}

void FAST_FUNC setup_environment(const char *shell, int clear_env, int change_env, const struct passwd *pw){	/* Change the current working directory to be the home directory	 * of the user */	if (chdir(pw->pw_dir)) {		xchdir("/");		bb_error_msg("can't chdir to home directory '%s'", pw->pw_dir);	}	if (clear_env) {		const char *term;		/* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH.		   Unset all other environment variables.  */		term = getenv("TERM");		clearenv();		if (term)			xsetenv("TERM", term);		xsetenv("PATH", (pw->pw_uid ? bb_default_path : bb_default_root_path));		goto shortcut;		// No, gcc (4.2.1) is not clever enougn to do it itself.		//xsetenv("USER",    pw->pw_name);		//xsetenv("LOGNAME", pw->pw_name);		//xsetenv("HOME",    pw->pw_dir);		//xsetenv("SHELL",   shell);	}	else if (change_env) {		/* Set HOME, SHELL, and if not becoming a super-user,		   USER and LOGNAME.  */		if (pw->pw_uid) { shortcut:			xsetenv("USER",    pw->pw_name);			xsetenv("LOGNAME", pw->pw_name);		}		xsetenv("HOME",    pw->pw_dir);		xsetenv("SHELL",   shell);	}}

int zcip_main(int argc UNUSED_PARAM, char **argv){	int state;	char *r_opt;	unsigned opts;	// ugly trick, but I want these zeroed in one go	struct {		const struct in_addr null_ip;		const struct ether_addr null_addr;		struct in_addr ip;		struct ifreq ifr;		int timeout_ms; /* must be signed */		unsigned conflicts;		unsigned nprobes;		unsigned nclaims;		int ready;	} L;#define null_ip    (L.null_ip   )#define null_addr  (L.null_addr )#define ip         (L.ip        )#define ifr        (L.ifr       )#define timeout_ms (L.timeout_ms)#define conflicts  (L.conflicts )#define nprobes    (L.nprobes   )#define nclaims    (L.nclaims   )#define ready      (L.ready     )	memset(&L, 0, sizeof(L));	INIT_G();#define FOREGROUND (opts & 1)#define QUIT       (opts & 2)	// parse commandline: prog [options] ifname script	// exactly 2 args; -v accumulates and implies -f	opt_complementary = "=2:vv:vf";	opts = getopt32(argv, "fqr:p:v", &r_opt, &pidfile, &verbose);#if !BB_MMU	// on NOMMU reexec early (or else we will rerun things twice)	if (!FOREGROUND)		bb_daemonize_or_rexec(0 /*was: DAEMON_CHDIR_ROOT*/, argv);#endif	// open an ARP socket	// (need to do it before openlog to prevent openlog from taking	// fd 3 (sock_fd==3))	xmove_fd(xsocket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)), sock_fd);	if (!FOREGROUND) {		// do it before all bb_xx_msg calls		openlog(applet_name, 0, LOG_DAEMON);		logmode |= LOGMODE_SYSLOG;	}	if (opts & 4) { // -r n.n.n.n		if (inet_aton(r_opt, &ip) == 0		 || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR		) {			bb_error_msg_and_die("invalid link address");		}	}	argv += optind - 1;	/* Now: argv[0]:junk argv[1]:intf argv[2]:script argv[3]:NULL */	/* We need to make space for script argument: */	argv[0] = argv[1];	argv[1] = argv[2];	/* Now: argv[0]:intf argv[1]:script argv[2]:junk argv[3]:NULL */#define argv_intf (argv[0])	xsetenv("interface", argv_intf);	// initialize the interface (modprobe, ifup, etc)	if (run(argv, "init", NULL))		return EXIT_FAILURE;	// initialize saddr	// saddr is: { u16 sa_family; u8 sa_data[14]; }	//memset(&saddr, 0, sizeof(saddr));	//TODO: are we leaving sa_family == 0 (AF_UNSPEC)?!	safe_strncpy(saddr.sa_data, argv_intf, sizeof(saddr.sa_data));	// bind to the interface's ARP socket	xbind(sock_fd, &saddr, sizeof(saddr));	// get the interface's ethernet address	//memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, argv_intf);	xioctl(sock_fd, SIOCGIFHWADDR, &ifr);	memcpy(&eth_addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);	// start with some stable ip address, either a function of	// the hardware address or else the last address we used.	// we are taking low-order four bytes, as top-order ones	// aren't random enough.	// NOTE: the sequence of addresses we try changes only	// depending on when we detect conflicts.	{		uint32_t t;		move_from_unaligned32(t, ((char *)&eth_addr + 2));		srand(t);	}	if (ip.s_addr == 0)//.........这里部分代码省略.........

//.........这里部分代码省略.........	/* Set CLASSPATH.  We don't use the "-classpath ..." option because	   in JDK 1.1.x its argument should also contain the JDK's classes.zip,	   but we don't know its location.  */	old_classpath =	  set_classpath (classpaths, classpaths_count, use_minimal_classpath,			 verbose);	argv[0] = "jre";	argv[1] = (char *) class_name;	for (i = 0; i <= nargs; i++)	  argv[2 + i] = (char *) args[i];	if (verbose)	  {	    char *command = shell_quote_argv (argv);	    printf ("%s/n", command);	    free (command);	  }	err = executer ("jre", "jre", argv, private_data);	/* Reset CLASSPATH.  */	reset_classpath (old_classpath);	freea (argv);	goto done2;      }  }#if defined _WIN32 || defined __WIN32__ || defined __CYGWIN__  /* Win32, Cygwin */  {    static bool jview_tested;    static bool jview_present;    if (!jview_tested)      {	/* Test for presence of jview: "jview -? >nul ; test $? = 1"  */	char *argv[3];	int exitstatus;	argv[0] = "jview";	argv[1] = "-?";	argv[2] = NULL;	exitstatus = execute ("jview", "jview", argv, false, false, true, true,			      true, false);	jview_present = (exitstatus == 0 || exitstatus == 1);	jview_tested = true;      }    if (jview_present)      {	char *old_classpath;	char **argv = (char **) xmalloca ((2 + nargs + 1) * sizeof (char *));	unsigned int i;	/* Set CLASSPATH.  */	old_classpath =	  set_classpath (classpaths, classpaths_count, use_minimal_classpath,			 verbose);	argv[0] = "jview";	argv[1] = (char *) class_name;	for (i = 0; i <= nargs; i++)	  argv[2 + i] = (char *) args[i];	if (verbose)	  {	    char *command = shell_quote_argv (argv);	    printf ("%s/n", command);	    free (command);	  }	err = executer ("jview", "jview", argv, private_data);	/* Reset CLASSPATH.  */	reset_classpath (old_classpath);	freea (argv);	goto done2;      }  }#endif  if (!quiet)    error (0, 0, _("Java virtual machine not found, try installing gij or set $JAVA"));  err = true; done2:  if (old_JAVA_HOME != NULL)    {      xsetenv ("JAVA_HOME", old_JAVA_HOME, 1);      free (old_JAVA_HOME);    } done1:  return err;}

//.........这里部分代码省略.........	if(b.len == 0) {		if(cansse2())			bwritestr(&b, "sse2");		else			bwritestr(&b, "387");	}	go386 = btake(&b);	p = bpathf(&b, "%s/include/u.h", goroot);	if(!isfile(p)) {		fatal("$GOROOT is not set correctly or not exported/n"			"/tGOROOT=%s/n"			"/t%s does not exist", goroot, p);	}	xgetenv(&b, "GOHOSTARCH");	if(b.len > 0)		gohostarch = btake(&b);	i = find(gohostarch, okgoarch, nelem(okgoarch));	if(i < 0)		fatal("unknown $GOHOSTARCH %s", gohostarch);	bprintf(&b, "%c", gochars[i]);	gohostchar = btake(&b);	xgetenv(&b, "GOARCH");	if(b.len == 0)		bwritestr(&b, gohostarch);	goarch = btake(&b);	i = find(goarch, okgoarch, nelem(okgoarch));	if(i < 0)		fatal("unknown $GOARCH %s", goarch);	bprintf(&b, "%c", gochars[i]);	gochar = btake(&b);	xgetenv(&b, "GO_EXTLINK_ENABLED");	if(b.len > 0) {		goextlinkenabled = btake(&b);		if(!streq(goextlinkenabled, "0") && !streq(goextlinkenabled, "1"))			fatal("unknown $GO_EXTLINK_ENABLED %s", goextlinkenabled);	}		xgetenv(&b, "CC");	if(b.len == 0) {		// Use clang on OS X, because gcc is deprecated there.		// Xcode for OS X 10.9 Mavericks will ship a fake "gcc" binary that		// actually runs clang. We prepare different command		// lines for the two binaries, so it matters what we call it.		// See golang.org/issue/5822.		if(defaultclang)			bprintf(&b, "clang");		else			bprintf(&b, "gcc");	}	defaultcc = btake(&b);	xgetenv(&b, "CFLAGS");	defaultcflags = btake(&b);	xgetenv(&b, "LDFLAGS");	defaultldflags = btake(&b);	xgetenv(&b, "CC_FOR_TARGET");	if(b.len == 0) {		bprintf(&b, defaultcc);	}	defaultcctarget = btake(&b);	xgetenv(&b, "CXX_FOR_TARGET");	if(b.len == 0) {		xgetenv(&b, "CXX");		if(b.len == 0) {			if(defaultclang)				bprintf(&b, "clang++");			else				bprintf(&b, "g++");		}	}	defaultcxxtarget = btake(&b);	xsetenv("GOROOT", goroot);	xsetenv("GOARCH", goarch);	xsetenv("GOOS", goos);	xsetenv("GOARM", goarm);	xsetenv("GO386", go386);	// Make the environment more predictable.	xsetenv("LANG", "C");	xsetenv("LANGUAGE", "en_US.UTF8");	goversion = findgoversion();	workdir = xworkdir();	xatexit(rmworkdir);	bpathf(&b, "%s/pkg/tool/%s_%s", goroot, gohostos, gohostarch);	tooldir = btake(&b);	bfree(&b);}

// init handles initialization of the various global state, like goroot and goarch.voidinit(void){	char *p;	int i;	Buf b;	binit(&b);	xgetenv(&b, "GOROOT");	if(b.len > 0) {		// if not "/", then strip trailing path separator		if(b.len >= 2 && b.p[b.len - 1] == slash[0])			b.len--;		goroot = btake(&b);	}	xgetenv(&b, "GOBIN");	if(b.len == 0)		bprintf(&b, "%s%sbin", goroot, slash);	gobin = btake(&b);	xgetenv(&b, "GOOS");	if(b.len == 0)		bwritestr(&b, gohostos);	goos = btake(&b);	if(find(goos, okgoos, nelem(okgoos)) < 0)		fatal("unknown $GOOS %s", goos);	p = bpathf(&b, "%s/include/u.h", goroot);	if(!isfile(p)) {		fatal("$GOROOT is not set correctly or not exported/n"			"/tGOROOT=%s/n"			"/t%s does not exist", goroot, p);	}	xgetenv(&b, "GOHOSTARCH");	if(b.len > 0)		gohostarch = btake(&b);	i = find(gohostarch, okgoarch, nelem(okgoarch));	if(i < 0)		fatal("unknown $GOHOSTARCH %s", gohostarch);	bprintf(&b, "%c", gochars[i]);	gohostchar = btake(&b);	xgetenv(&b, "GOARCH");	if(b.len == 0)		bwritestr(&b, gohostarch);	goarch = btake(&b);	i = find(goarch, okgoarch, nelem(okgoarch));	if(i < 0)		fatal("unknown $GOARCH %s", goarch);	bprintf(&b, "%c", gochars[i]);	gochar = btake(&b);	xsetenv("GOROOT", goroot);	xsetenv("GOARCH", goarch);	xsetenv("GOOS", goos);	// Make the environment more predictable.	xsetenv("LANG", "C");	xsetenv("LANGUAGE", "en_US.UTF8");	goversion = findgoversion();	workdir = xworkdir();	xatexit(rmworkdir);	bpathf(&b, "%s/pkg/tool/%s_%s", goroot, gohostos, gohostarch);	tooldir = btake(&b);	bfree(&b);}

static void xsetenv_if_unset(const char *key, const char *value){	if (!getenv(key))		xsetenv(key, value);}

static int parse(const char *boundary, char **argv){	char *line, *s, *p;	const char *type;	int boundary_len = strlen(boundary);	const char *delims = " ;/"/t/r/n";	const char *uniq;	int ntokens;	const char *tokens[32]; // 32 is enough	// prepare unique string pattern	uniq = xasprintf("%%llu.%u.%s", (unsigned)getpid(), safe_gethostname());//bb_info_msg("PARSE[%s]", terminator);	while ((line = xmalloc_fgets_str(stdin, "/r/n/r/n")) != NULL) {		// seek to start of MIME section		// N.B. to avoid false positives let us seek to the _last_ occurance		p = NULL;		s = line;		while ((s=strcasestr(s, "Content-Type:")) != NULL)			p = s++;		if (!p)			goto next;//bb_info_msg("L[%s]", p);		// split to tokens		// TODO: strip of comments which are of form: (comment-text)		ntokens = 0;		tokens[ntokens] = NULL;		for (s = strtok(p, delims); s; s = strtok(NULL, delims)) {			tokens[ntokens] = s;			if (ntokens < ARRAY_SIZE(tokens) - 1)				ntokens++;//bb_info_msg("L[%d][%s]", ntokens, s);		}		tokens[ntokens] = NULL;//bb_info_msg("N[%d]", ntokens);		// analyse tokens		type = find_token(tokens, "Content-Type:", "text/plain");//bb_info_msg("T[%s]", type);		if (0 == strncasecmp(type, "multipart/", 10)) {			if (0 == strcasecmp(type+10, "mixed")) {				parse(xfind_token(tokens, "boundary="), argv);			} else				bb_error_msg_and_die("no support of content type '%s'", type);		} else {			pid_t pid = pid;			int rc;			FILE *fp;			// fetch charset			const char *charset = find_token(tokens, "charset=", CONFIG_FEATURE_MIME_CHARSET);			// fetch encoding			const char *encoding = find_token(tokens, "Content-Transfer-Encoding:", "7bit");			// compose target filename			char *filename = (char *)find_token(tokens, "filename=", NULL);			if (!filename)				filename = xasprintf(uniq, monotonic_us());			else				filename = bb_get_last_path_component_strip(xstrdup(filename));			// start external helper, if any			if (opts & OPT_X) {				int fd[2];				xpipe(fd);				pid = vfork();				if (0 == pid) {					// child reads from fd[0]					xdup2(fd[0], STDIN_FILENO);					close(fd[0]); close(fd[1]);					xsetenv("CONTENT_TYPE", type);					xsetenv("CHARSET", charset);					xsetenv("ENCODING", encoding);					xsetenv("FILENAME", filename);					BB_EXECVP(*argv, argv);					_exit(EXIT_FAILURE);				}				// parent dumps to fd[1]				close(fd[0]);				fp = fdopen(fd[1], "w");				signal(SIGPIPE, SIG_IGN); // ignore EPIPE			// or create a file for dump			} else {				char *fname = xasprintf("%s%s", *argv, filename);				fp = xfopen_for_write(fname);				free(fname);			}			// housekeeping			free(filename);			// dump to fp			if (0 == strcasecmp(encoding, "base64")) {				decode_base64(stdin, fp);			} else if (0 != strcasecmp(encoding, "7bit")				&& 0 != strcasecmp(encoding, "8bit")) {				// quoted-printable, binary, user-defined are unsupported so far				bb_error_msg_and_die("no support of encoding '%s'", encoding);//.........这里部分代码省略.........