commands.c

经典的unix下telnet的c代码

}

    int
tn_setmode(bit)
{
    return dolmmode(bit, 1);
}

    int
tn_clearmode(bit)
{
    return dolmmode(bit, 0);
}

struct modelist {
	char	*name;		/* command name */
	char	*help;		/* help string */
	int	(*handler)();	/* routine which executes command */
	int	needconnect;	/* Do we need to be connected to execute? */
	int	arg1;
};

static int modehelp(void);

static struct modelist ModeList[] = {
    { "character", "Disable LINEMODE option",	docharmode, 1 },
#ifdef	KLUDGELINEMODE
    { "",	"(or disable obsolete line-by-line mode)", 0 },
#endif
    { "line",	"Enable LINEMODE option",	dolinemode, 1 },
#ifdef	KLUDGELINEMODE
    { "",	"(or enable obsolete line-by-line mode)", 0 },
#endif
    { "", "", 0 },
    { "",	"These require the LINEMODE option to be enabled", 0 },
    { "isig",	"Enable signal trapping",	tn_setmode, 1, MODE_TRAPSIG },
    { "+isig",	0,				tn_setmode, 1, MODE_TRAPSIG },
    { "-isig",	"Disable signal trapping",	tn_clearmode, 1, MODE_TRAPSIG },
    { "edit",	"Enable character editing",	tn_setmode, 1, MODE_EDIT },
    { "+edit",	0,				tn_setmode, 1, MODE_EDIT },
    { "-edit",	"Disable character editing",	tn_clearmode, 1, MODE_EDIT },
    { "softtabs", "Enable tab expansion",	tn_setmode, 1, MODE_SOFT_TAB },
    { "+softtabs", 0,				tn_setmode, 1, MODE_SOFT_TAB },
    { "-softtabs", "Disable character editing",	tn_clearmode, 1, MODE_SOFT_TAB },
    { "litecho", "Enable literal character echo", tn_setmode, 1, MODE_LIT_ECHO },
    { "+litecho", 0,				tn_setmode, 1, MODE_LIT_ECHO },
    { "-litecho", "Disable literal character echo", tn_clearmode, 1, MODE_LIT_ECHO },
    { "help",	0,				modehelp, 0 },
#ifdef	KLUDGELINEMODE
    { "kludgeline", 0,				dokludgemode, 1 },
#endif
    { "", "", 0 },
    { "?",	"Print help information",	modehelp, 0 },
    { 0 },
};


    static int
modehelp()
{
    struct modelist *mt;

    printf("format is:  'mode Mode', where 'Mode' is one of:\r\n\r\n");
    for (mt = ModeList; mt->name; mt++) {
	if (mt->help) {
	    if (*mt->help)
		printf("%-15s %s\r\n", mt->name, mt->help);
	    else
		printf("\r\n");
	}
    }
    return 0;
}

#define	GETMODECMD(name) (struct modelist *) \
		genget(name, (char **) ModeList, sizeof(struct modelist))

    static int
modecmd(argc, argv)
    int  argc;
    char *argv[];
{
    struct modelist *mt;

    if (argc != 2) {
	printf("'mode' command requires an argument\r\n");
	printf("'mode ?' for help.\r\n");
    } else if ((mt = GETMODECMD(argv[1])) == 0) {
	fprintf(stderr, "Unknown mode '%s' ('mode ?' for help).\r\n", argv[1]);
    } else if (Ambiguous(mt)) {
	fprintf(stderr, "Ambiguous mode '%s' ('mode ?' for help).\r\n", argv[1]);
    } else if (mt->needconnect && !connected) {
	printf("?Need to be connected first.\r\n");
	printf("'mode ?' for help.\r\n");
    } else if (mt->handler) {
	return (*mt->handler)(mt->arg1);
    }
    return 0;
}

/*
 * The following data structures and routines implement the
 * "display" command.
 */

    static int
display(argc, argv)
    int  argc;
    char *argv[];
{
    struct togglelist *tl;
    struct setlist *sl;

#define	dotog(tl)	if (tl->variable && tl->actionexplanation) { \
			    if (*tl->variable) { \
				printf("will"); \
			    } else { \
				printf("won't"); \
			    } \
			    printf(" %s.\r\n", tl->actionexplanation); \
			}

#define	doset(sl)   if (sl->name && *sl->name != ' ') { \
			if (sl->handler == 0) \
			    printf("%-15s [%s]\r\n", sl->name, control(*sl->charp)); \
			else \
			    printf("%-15s \"%s\"\r\n", sl->name, (char *)sl->charp); \
		    }

    if (argc == 1) {
	for (tl = Togglelist; tl->name; tl++) {
	    dotog(tl);
	}
	printf("\r\n");
	for (sl = Setlist; sl->name; sl++) {
	    doset(sl);
	}
    } else {
	int i;

	for (i = 1; i < argc; i++) {
	    sl = getset(argv[i]);
	    tl = GETTOGGLE(argv[i]);
	    if (Ambiguous(sl) || Ambiguous(tl)) {
		printf("?Ambiguous argument '%s'.\r\n", argv[i]);
		return 0;
	    } else if (!sl && !tl) {
		printf("?Unknown argument '%s'.\r\n", argv[i]);
		return 0;
	    } else {
		if (tl) {
		    dotog(tl);
		}
		if (sl) {
		    doset(sl);
		}
	    }
	}
    }
/*@*/optionstatus();
#if    defined(ENCRYPTION)
    EncryptStatus();
#endif
    return 1;
#undef	doset
#undef	dotog
}

/*
 * The following are the data structures, and many of the routines,
 * relating to command processing.
 */

/*
 * Set the escape character.
 */
	static int
setescape(argc, argv)
	int argc;
	char *argv[];
{
	char *arg;
	char buf[50];

	printf(
	    "Deprecated usage - please use 'set escape%s%s' in the future.\r\n",
				(argc > 2)? " ":"", (argc > 2)? argv[1]: "");
	if (argc > 2)
		arg = argv[1];
	else {
		printf("new escape character: ");
		(void) fgets(buf, sizeof(buf), stdin);
		arg = buf;
	}
	if (arg[0] != '\0')
		escape = arg[0];
	if (!In3270) {
		printf("Escape character is '%s'.\r\n", control(escape));
	}
	(void) fflush(stdout);
	return 1;
}

    /*VARARGS*/
    static int
togcrmod()
{
    crmod = !crmod;
    printf("Deprecated usage - please use 'toggle crmod' in the future.\r\n");
    printf("%s map carriage return on output.\r\n", crmod ? "Will" : "Won't");
    (void) fflush(stdout);
    return 1;
}

    /*VARARGS*/
    int
telnetsuspend()
{
#ifdef	SIGTSTP
    setcommandmode();
    {
	long oldrows, oldcols, newrows, newcols, err;

	err = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
	(void) kill(0, SIGTSTP);
	/*
	 * If we didn't get the window size before the SUSPEND, but we
	 * can get them now (?), then send the NAWS to make sure that
	 * we are set up for the right window size.
	 */
	if (TerminalWindowSize(&newrows, &newcols) && connected &&
	    (err || ((oldrows != newrows) || (oldcols != newcols)))) {
		sendnaws();
	}
    }
    /* reget parameters in case they were changed */
    TerminalSaveState();
    setconnmode(0);
#else
    printf("Suspend is not supported.  Try the '!' command instead\r\n");
#endif
    return 1;
}

#if	!defined(TN3270)
    /*ARGSUSED*/
    int
shell(argc, argv)
    int argc;
    char *argv[];
{
    long oldrows, oldcols, newrows, newcols, err;

    setcommandmode();

    err = (TerminalWindowSize(&oldrows, &oldcols) == 0) ? 1 : 0;
    switch(vfork()) {
    case -1:
	perror("Fork failed\r\n");
	break;

    case 0:
	{
	    /*
	     * Fire up the shell in the child.
	     */
	    char *shellp, *shellname;

	    shellp = getenv("SHELL");
	    if (shellp == NULL)
		shellp = "/bin/sh";
	    if ((shellname = strrchr(shellp, '/')) == 0)
		shellname = shellp;
	    else
		shellname++;
	    if (argc > 1)
		execl(shellp, shellname, "-c", &saveline[1], (char *)NULL);
	    else
		execl(shellp, shellname, (char *)NULL);
	    perror("Execl");
	    _exit(1);
	}
    default:
	    (void)wait((int *)0);	/* Wait for the shell to complete */

	    if (TerminalWindowSize(&newrows, &newcols) && connected &&
		(err || ((oldrows != newrows) || (oldcols != newcols)))) {
		    sendnaws();
	    }
	    break;
    }
    return 1;
}
#else	/* !defined(TN3270) */
extern int shell();
#endif	/* !defined(TN3270) */

    /*VARARGS*/
    static int
bye(argc, argv)
    int  argc;		/* Number of arguments */
    char *argv[];	/* arguments */
{
    extern int resettermname;

    if (connected) {
	(void) shutdown(net, 2);
	printf("Connection closed.\r\n");
	(void) NetClose(net);
	connected = 0;
	resettermname = 1;
#if	defined(AUTHENTICATION) || defined(ENCRYPTION)
	auth_encrypt_connect(connected);
#endif	/* defined(AUTHENTICATION) */
	/* reset options */
	tninit();
#if	defined(TN3270)
	SetIn3270();		/* Get out of 3270 mode */
#endif	/* defined(TN3270) */
    }
    if ((argc != 2) || (strcmp(argv[1], "fromquit") != 0)) {
	longjmp(toplevel, 1);
	/* NOTREACHED */
    }
    return 0; /* NOTREACHED */
}

/*VARARGS*/
	int
quit()
{
	(void) call(bye, "bye", "fromquit", 0);
	Exit(0);
	return 0; /*NOTREACHED*/
}

/*VARARGS*/
	static int
logout()
{
	send_do(TELOPT_LOGOUT, 1);
	(void) netflush();
	return 1;
}


/*
 * The SLC command.
 */

struct slclist {
	char	*name;
	char	*help;
	void	(*handler)();
	int	arg;
};

static void slc_help();

struct slclist SlcList[] = {
    { "export",	"Use local special character definitions",
						slc_mode_export,	0 },
    { "import",	"Use remote special character definitions",
						slc_mode_import,	1 },
    { "check",	"Verify remote special character definitions",
						slc_mode_import,	0 },
    { "help",	0,				slc_help,		0 },
    { "?",	"Print help information",	slc_help,		0 },
    { 0 },
};

    static void
slc_help()
{
    struct slclist *c;

    for (c = SlcList; c->name; c++) {
	if (c->help) {
	    if (*c->help)
		printf("%-15s %s\r\n", c->name, c->help);
	    else
		printf("\r\n");
	}
    }
}

    static struct slclist *
getslc(name)
    char *name;
{
    return (struct slclist *)
		genget(name, (char **) SlcList, sizeof(struct slclist));
}

    static int
slccmd(argc, argv)
    int  argc;
    char *argv[];
{
    struct slclist *c;

    if (argc != 2) {
	fprintf(stderr,
	    "Need an argument to 'slc' command.  'slc ?' for help.\r\n");
	return 0;
    }
    c = getslc(argv[1]);
    if (c == 0) {
	fprintf(stderr, "'%s': unknown argument ('slc ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    if (Ambiguous(c)) {
	fprintf(stderr, "'%s': ambiguous argument ('slc ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    (*c->handler)(c->arg);
    slcstate();
    return 1;
}

/*
 * The ENVIRON command.
 */

struct envlist {
	char	*name;
	char	*help;
	void	(*handler)();
	int	narg;
};

static void	env_help(void);

struct envlist EnvList[] = {
    { "define",	"Define an environment variable",
						(void (*)())env_define,	2 },
    { "undefine", "Undefine an environment variable",
						env_undefine,	1 },
    { "export",	"Mark an environment variable for automatic export",
						env_export,	1 },
    { "unexport", "Don't mark an environment variable for automatic export",
						env_unexport,	1 },
    { "send",	"Send an environment variable", env_send,	1 },
    { "list",	"List the current environment variables",
						env_list,	0 },
#if defined(OLD_ENVIRON) && defined(ENV_HACK)
    { "varval", "Reverse VAR and VALUE (auto, right, wrong, status)",
						env_varval,    1 },
#endif
    { "help",	0,				env_help,		0 },
    { "?",	"Print help information",	env_help,		0 },
    { 0 },
};

    static void
env_help()
{
    struct envlist *c;

    for (c = EnvList; c->name; c++) {
	if (c->help) {
	    if (*c->help)
		printf("%-15s %s\r\n", c->name, c->help);
	    else
		printf("\r\n");
	}
    }
}

    static struct envlist *
getenvcmd(name)
    char *name;
{
    return (struct envlist *)
		genget(name, (char **) EnvList, sizeof(struct envlist));
}

    int
env_cmd(argc, argv)
    int  argc;
    char *argv[];
{
    struct envlist *c;

    if (argc < 2) {
	fprintf(stderr,
	    "Need an argument to 'environ' command.  'environ ?' for help.\r\n");
	return 0;
    }
    c = getenvcmd(argv[1]);
    if (c == 0) {
	fprintf(stderr, "'%s': unknown argument ('environ ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    if (Ambiguous(c)) {
	fprintf(stderr, "'%s': ambiguous argument ('environ ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    if (c->narg + 2 != argc) {
	fprintf(stderr,
	    "Need %s%d argument%s to 'environ %s' command.  'environ ?' for help.\r\n",
		c->narg < argc + 2 ? "only " : "",
		c->narg, c->narg == 1 ? "" : "s", c->name);
	return 0;
    }
    (*c->handler)(argv[2], argv[3]);
    return 1;
}

struct env_lst {
	struct env_lst *next;	/* pointer to next structure */
	struct env_lst *prev;	/* pointer to previous structure */
	unsigned char *var;	/* pointer to variable name */
	unsigned char *value;	/* pointer to variable value */
	int export;		/* 1 -> export with default list of variables */
	int welldefined;	/* A well defined variable */
};

struct env_lst envlisthead;

	struct env_lst *
env_find(var)
	unsigned char *var;
{
	struct env_lst *ep;

	for (ep = envlisthead.next; ep; ep = ep->next) {
		if (strcmp((char *)ep->var, (char *)var) == 0)
			return(ep);
	}
	return(NULL);
}

	void
env_init()
{
	extern char **environ;
	char **epp, *cp;
	struct env_lst *ep;

	for (epp = environ; *epp; epp++) {
		if ((cp = strchr(*epp, '='))) {
			*cp = '\0';
			ep = env_define((unsigned char *)*epp,
					(unsigned char *)cp+1);
			ep->export = 0;
			*cp = '=';
		}