command.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

		opt1 = psql_scan_slash_option(scan_state,
									  OT_NORMAL, NULL, true);
		opt2 = psql_scan_slash_option(scan_state,
									  OT_NORMAL, NULL, true);

		if (strcmp(cmd + 3, "export") == 0)
		{
			if (!opt2)
			{
				psql_error("\\%s: missing required argument\n", cmd);
				success = false;
			}
			else
			{
				expand_tilde(&opt2);
				success = do_lo_export(opt1, opt2);
			}
		}

		else if (strcmp(cmd + 3, "import") == 0)
		{
			if (!opt1)
			{
				psql_error("\\%s: missing required argument\n", cmd);
				success = false;
			}
			else
			{
				expand_tilde(&opt1);
				success = do_lo_import(opt1, opt2);
			}
		}

		else if (strcmp(cmd + 3, "list") == 0)
			success = do_lo_list();

		else if (strcmp(cmd + 3, "unlink") == 0)
		{
			if (!opt1)
			{
				psql_error("\\%s: missing required argument\n", cmd);
				success = false;
			}
			else
				success = do_lo_unlink(opt1);
		}

		else
			status = CMD_UNKNOWN;

		free(opt1);
		free(opt2);
	}


	/* \o -- set query output */
	else if (strcmp(cmd, "o") == 0 || strcmp(cmd, "out") == 0)
	{
		char	   *fname = psql_scan_slash_option(scan_state,
												   OT_FILEPIPE, NULL, true);

		expand_tilde(&fname);
		success = setQFout(fname);
		free(fname);
	}

	/* \p prints the current query buffer */
	else if (strcmp(cmd, "p") == 0 || strcmp(cmd, "print") == 0)
	{
		if (query_buf && query_buf->len > 0)
			puts(query_buf->data);
		else if (!quiet)
			puts(_("Query buffer is empty."));
		fflush(stdout);
	}

	/* \pset -- set printing parameters */
	else if (strcmp(cmd, "pset") == 0)
	{
		char	   *opt0 = psql_scan_slash_option(scan_state,
												  OT_NORMAL, NULL, false);
		char	   *opt1 = psql_scan_slash_option(scan_state,
												  OT_NORMAL, NULL, false);

		if (!opt0)
		{
			psql_error("\\%s: missing required argument\n", cmd);
			success = false;
		}
		else
			success = do_pset(opt0, opt1, &pset.popt, quiet);

		free(opt0);
		free(opt1);
	}

	/* \q or \quit */
	else if (strcmp(cmd, "q") == 0 || strcmp(cmd, "quit") == 0)
		status = CMD_TERMINATE;

	/* reset(clear) the buffer */
	else if (strcmp(cmd, "r") == 0 || strcmp(cmd, "reset") == 0)
	{
		resetPQExpBuffer(query_buf);
		psql_scan_reset(scan_state);
		if (!quiet)
			puts(_("Query buffer reset (cleared)."));
	}

	/* \s save history in a file or show it on the screen */
	else if (strcmp(cmd, "s") == 0)
	{
		char	   *fname = psql_scan_slash_option(scan_state,
												   OT_NORMAL, NULL, true);

		expand_tilde(&fname);
		/* This scrolls off the screen when using /dev/tty */
		success = saveHistory(fname ? fname : DEVTTY);
		if (success && !quiet && fname)
			printf(gettext("Wrote history to file \"%s/%s\".\n"),
				   pset.dirname ? pset.dirname : ".", fname);
		if (!fname)
			putchar('\n');
		free(fname);
	}

	/* \set -- generalized set variable/option command */
	else if (strcmp(cmd, "set") == 0)
	{
		char	   *opt0 = psql_scan_slash_option(scan_state,
												  OT_NORMAL, NULL, false);

		if (!opt0)
		{
			/* list all variables */
			PrintVariables(pset.vars);
			success = true;
		}
		else
		{
			/*
			 * Set variable to the concatenation of the arguments.
			 */
			char	   *newval;
			char	   *opt;

			opt = psql_scan_slash_option(scan_state,
										 OT_NORMAL, NULL, false);
			newval = pg_strdup(opt ? opt : "");
			free(opt);

			while ((opt = psql_scan_slash_option(scan_state,
												 OT_NORMAL, NULL, false)))
			{
				newval = realloc(newval, strlen(newval) + strlen(opt) + 1);
				if (!newval)
				{
					psql_error("out of memory\n");
					exit(EXIT_FAILURE);
				}
				strcat(newval, opt);
				free(opt);
			}

			if (SetVariable(pset.vars, opt0, newval))
			{
				/* Check for special variables */
				if (strcmp(opt0, "VERBOSITY") == 0)
					SyncVerbosityVariable();
			}
			else
			{
				psql_error("\\%s: error\n", cmd);
				success = false;
			}
			free(newval);
		}
		free(opt0);
	}

	/* \t -- turn off headers and row count */
	else if (strcmp(cmd, "t") == 0)
		success = do_pset("tuples_only", NULL, &pset.popt, quiet);


	/* \T -- define html <table ...> attributes */
	else if (strcmp(cmd, "T") == 0)
	{
		char	   *value = psql_scan_slash_option(scan_state,
												   OT_NORMAL, NULL, false);

		success = do_pset("tableattr", value, &pset.popt, quiet);
		free(value);
	}

	/* \timing -- toggle timing of queries */
	else if (strcmp(cmd, "timing") == 0)
	{
		pset.timing = !pset.timing;
		if (!quiet)
		{
			if (pset.timing)
				puts(_("Timing is on."));
			else
				puts(_("Timing is off."));
		}
	}

	/* \unset */
	else if (strcmp(cmd, "unset") == 0)
	{
		char	   *opt = psql_scan_slash_option(scan_state,
												 OT_NORMAL, NULL, false);

		if (!opt)
		{
			psql_error("\\%s: missing required argument\n", cmd);
			success = false;
		}
		else if (!SetVariable(pset.vars, opt, NULL))
		{
			psql_error("\\%s: error\n", cmd);
			success = false;
		}
		free(opt);
	}

	/* \w -- write query buffer to file */
	else if (strcmp(cmd, "w") == 0 || strcmp(cmd, "write") == 0)
	{
		FILE	   *fd = NULL;
		bool		is_pipe = false;
		char	   *fname = NULL;

		if (!query_buf)
		{
			psql_error("no query buffer\n");
			status = CMD_ERROR;
		}
		else
		{
			fname = psql_scan_slash_option(scan_state,
										   OT_FILEPIPE, NULL, true);
			expand_tilde(&fname);

			if (!fname)
			{
				psql_error("\\%s: missing required argument\n", cmd);
				success = false;
			}
			else
			{
				if (fname[0] == '|')
				{
					is_pipe = true;
					fd = popen(&fname[1], "w");
				}
				else
				{
					canonicalize_path(fname);
					fd = fopen(fname, "w");
				}
				if (!fd)
				{
					psql_error("%s: %s\n", fname, strerror(errno));
					success = false;
				}
			}
		}

		if (fd)
		{
			int			result;

			if (query_buf && query_buf->len > 0)
				fprintf(fd, "%s\n", query_buf->data);

			if (is_pipe)
				result = pclose(fd);
			else
				result = fclose(fd);

			if (result == EOF)
			{
				psql_error("%s: %s\n", fname, strerror(errno));
				success = false;
			}
		}

		free(fname);
	}

	/* \x -- toggle expanded table representation */
	else if (strcmp(cmd, "x") == 0)
		success = do_pset("expanded", NULL, &pset.popt, quiet);

	/* \z -- list table rights (equivalent to \dp) */
	else if (strcmp(cmd, "z") == 0)
	{
		char	   *pattern = psql_scan_slash_option(scan_state,
													 OT_NORMAL, NULL, true);

		success = permissionsList(pattern);
		if (pattern)
			free(pattern);
	}

	/* \! -- shell escape */
	else if (strcmp(cmd, "!") == 0)
	{
		char	   *opt = psql_scan_slash_option(scan_state,
												 OT_WHOLE_LINE, NULL, false);

		success = do_shell(opt);
		free(opt);
	}

	/* \? -- slash command help */
	else if (strcmp(cmd, "?") == 0)
		slashUsage(pset.popt.topt.pager);

#if 0

	/*
	 * These commands don't do anything. I just use them to test the parser.
	 */
	else if (strcmp(cmd, "void") == 0 || strcmp(cmd, "#") == 0)
	{
		int			i = 0;
		char	   *value;

		while ((value = psql_scan_slash_option(scan_state,
											   OT_NORMAL, NULL, true)))
		{
			fprintf(stderr, "+ opt(%d) = |%s|\n", i++, value);
			free(value);
		}
	}
#endif

	else
		status = CMD_UNKNOWN;

	if (!success)
		status = CMD_ERROR;

	return status;
}



/* do_connect
 * -- handler for \connect
 *
 * Connects to a database (new_dbname) as a certain user (new_user).
 * The new user can be NULL. A db name of "-" is the same as the old one.
 * (That is, the one currently in pset. But pset.db can also be NULL. A NULL
 * dbname is handled by libpq.)
 * Returns true if all ok, false if the new connection couldn't be established.
 * The old connection will be kept if the session is interactive.
 */
static bool
do_connect(const char *new_dbname, const char *new_user)
{
	PGconn	   *oldconn = pset.db;
	const char *dbparam = NULL;
	const char *userparam = NULL;
	const char *pwparam = NULL;
	char	   *password_prompt = NULL;
	char	   *prompted_password = NULL;
	bool		need_pass;
	bool		success = false;

	/* Delete variables (in case we fail before setting them anew) */
	UnsyncVariables();

	/* If dbname is "" then use old name, else new one (even if NULL) */
	if (oldconn && new_dbname && PQdb(oldconn) && strcmp(new_dbname, "") == 0)
		dbparam = PQdb(oldconn);
	else
		dbparam = new_dbname;

	/* If user is "" then use the old one */
	if (new_user && PQuser(oldconn) && strcmp(new_user, "") == 0)
		userparam = PQuser(oldconn);
	else
		userparam = new_user;

	if (userparam == NULL)
		password_prompt = strdup("Password: ");
	else
	{
		password_prompt = malloc(strlen(_("Password for user %s: ")) - 2 +
								 strlen(userparam) + 1);
		sprintf(password_prompt, _("Password for user %s: "), userparam);
	}

	/* need to prompt for password? */
	if (pset.getPassword)
		pwparam = prompted_password = simple_prompt(password_prompt, 100, false);

	/*
	 * Use old password (if any) if no new one given and we are reconnecting
	 * as same user
	 */
	if (!pwparam && oldconn && PQuser(oldconn) && userparam &&
		strcmp(PQuser(oldconn), userparam) == 0)
		pwparam = PQpass(oldconn);

	do
	{
		need_pass = false;
		pset.db = PQsetdbLogin(PQhost(oldconn), PQport(oldconn),
							   NULL, NULL, dbparam, userparam, pwparam);

		if (PQstatus(pset.db) == CONNECTION_BAD &&
			strcmp(PQerrorMessage(pset.db), PQnoPasswordSupplied) == 0 &&
			!feof(stdin))
		{
			PQfinish(pset.db);
			need_pass = true;
			free(prompted_password);
			prompted_password = NULL;
			pwparam = prompted_password = simple_prompt(password_prompt, 100, false);
		}
	} while (need_pass);

	free(prompted_password);
	free(password_prompt);

	/*
	 * If connection failed, try at least keep the old one. That's probably
	 * more convenient than just kicking you out of the program.
	 */
	if (!pset.db || PQstatus(pset.db) == CONNECTION_BAD)
	{
		if (pset.cur_cmd_interactive)
		{
			psql_error("%s", PQerrorMessage(pset.db));
			PQfinish(pset.db);
			if (oldconn)
			{
				fputs(_("Previous connection kept\n"), stderr);
				pset.db = oldconn;
			}
			else
				pset.db = NULL;
		}
		else
		{
			/*
			 * we don't want unpredictable things to happen in scripting mode
			 */
			psql_error("\\connect: %s", PQerrorMessage(pset.db));
			PQfinish(pset.db);
			if (oldconn)
				PQfinish(oldconn);
			pset.db = NULL;
		}
	}
	else
	{
		if (!QUIET())
		{
			if (userparam != new_user)	/* no new user */
				printf(_("You are now connected to database \"%s\".\n"), dbparam);
			else if (dbparam != new_dbname)		/* no new db */
				printf(_("You are now connected as new user \"%s\".\n"), new_user);
			else
				/* both new */
				printf(_("You are now connected to database \"%s\" as user \"%s\".\n"),
					   PQdb(pset.db), PQuser(pset.db));
		}

		if (oldconn)
			PQfinish(oldconn);

		success = true;
	}

	PQsetNoticeProcessor(pset.db, NoticeProcessor, NULL);

	/* Update variables */
	SyncVariables();

	return success;
}


/*
 * SyncVariables
 *
 * Make psql's internal variables agree with connection state upon
 * establishing a new connection.
 */
void
SyncVariables(void)
{
	/* get stuff from connection */
	pset.encoding = PQclientEncoding(pset.db);
	pset.popt.topt.encoding = pset.encoding;

	SetVariable(pset.vars, "DBNAME", PQdb(pset.db));
	SetVariable(pset.vars, "USER", PQuser(pset.db));
	SetVariable(pset.vars, "HOST", PQhost(pset.db));
	SetVariable(pset.vars, "PORT", PQport(pset.db));
	SetVariable(pset.vars, "ENCODING", pg_encoding_to_char(pset.encoding));

	/* send stuff to it, too */
	SyncVerbosityVariable();
}

/*
 * UnsyncVariables
 *
 * Clear variables that should be not be set when there is no connection.
 */
void
UnsyncVariables(void)
{
	SetVariable(pset.vars, "DBNAME", NULL);
	SetVariable(pset.vars, "USER", NULL);
	SetVariable(pset.vars, "HOST", NULL);
	SetVariable(pset.vars, "PORT", NULL);
	SetVariable(pset.vars, "ENCODING", NULL);
}

/*
 * Update connection state from VERBOSITY variable
 */
void
SyncVerbosityVariable(void)
{
	switch (SwitchVariable(pset.vars, "VERBOSITY",
						   "default", "terse", "verbose", NULL))
	{
		case 1:			/* default */
			pset.verbosity = PQERRORS_DEFAULT;
			break;
		case 2:			/* terse */
			pset.verbosity = PQERRORS_TERSE;
			break;
		case 3:			/* verbose */
			pset.verbosity = PQERRORS_VERBOSE;