command.c

PostgreSQL7.4.6 for Linux

/*
 * psql - the PostgreSQL interactive terminal
 *
 * Copyright (c) 2000-2003, PostgreSQL Global Development Group
 *
 * $Header: /cvsroot/pgsql/src/bin/psql/command.c,v 1.105 2003/10/11 18:04:26 momjian Exp $
 */
#include "postgres_fe.h"
#include "command.h"

#include <errno.h>
#include <assert.h>
#include <ctype.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifndef WIN32
#include <sys/types.h>			/* for umask() */
#include <sys/stat.h>			/* for stat() */
#include <fcntl.h>				/* open() flags */
#include <unistd.h>				/* for geteuid(), getpid(), stat() */
#else
#include <win32.h>
#include <io.h>
#include <fcntl.h>
#include <direct.h>
#endif

#include "libpq-fe.h"
#include "pqexpbuffer.h"

#include "common.h"
#include "copy.h"
#include "describe.h"
#include "help.h"
#include "input.h"
#include "large_obj.h"
#include "mainloop.h"
#include "print.h"
#include "settings.h"
#include "variables.h"
#include "mb/pg_wchar.h"

/* functions for use in this file */

static backslashResult exec_command(const char *cmd,
			 const char *options_string,
			 const char **continue_parse,
			 PQExpBuffer query_buf,
			 volatile int *paren_level);

/* different ways for scan_option to handle parameter words */
enum option_type
{
	OT_NORMAL,					/* normal case */
	OT_SQLID,					/* treat as SQL identifier */
	OT_SQLIDHACK,				/* SQL identifier, but don't downcase */
	OT_FILEPIPE					/* it's a filename or pipe */
};

static char *scan_option(char **string, enum option_type type,
			char *quote, bool semicolon);
static char *unescape(const unsigned char *source, size_t len);

static bool do_edit(const char *filename_arg, PQExpBuffer query_buf);
static bool do_connect(const char *new_dbname, const char *new_user);
static bool do_shell(const char *command);

/*----------
 * HandleSlashCmds:
 *
 * Handles all the different commands that start with '\',
 * ordinarily called by MainLoop().
 *
 * 'line' is the current input line, which should not start with a '\'
 * but with the actual command name
 * (that is taken care of by MainLoop)
 *
 * 'query_buf' contains the query-so-far, which may be modified by
 * execution of the backslash command (for example, \r clears it)
 * query_buf can be NULL if there is no query so far.
 *
 * Returns a status code indicating what action is desired, see command.h.
 *----------
 */

backslashResult
HandleSlashCmds(const char *line,
				PQExpBuffer query_buf,
				const char **end_of_cmd,
				volatile int *paren_level)
{
	backslashResult status = CMD_SKIP_LINE;
	char	   *my_line;
	char	   *options_string = NULL;
	size_t		blank_loc;
	const char *continue_parse = NULL;	/* tell the mainloop where the
										 * backslash command ended */

#ifdef USE_ASSERT_CHECKING
	assert(line);
#endif

	my_line = xstrdup(line);

	/*
	 * Find the first whitespace. line[blank_loc] will now be the
	 * whitespace character or the \0 at the end
	 *
	 * Also look for a backslash, so stuff like \p\g works.
	 */
	blank_loc = strcspn(my_line, " \t\n\r\\");

	if (my_line[blank_loc] == '\\')
	{
		continue_parse = &my_line[blank_loc];
		my_line[blank_loc] = '\0';
		/* If it's a double backslash, we skip it. */
		if (my_line[blank_loc + 1] == '\\')
			continue_parse += 2;
	}
	/* do we have an option string? */
	else if (my_line[blank_loc] != '\0')
	{
		options_string = &my_line[blank_loc + 1];
		my_line[blank_loc] = '\0';
	}

	status = exec_command(my_line, options_string, &continue_parse, query_buf, paren_level);

	if (status == CMD_UNKNOWN)
	{
		/*
		 * If the command was not recognized, try to parse it as a
		 * one-letter command with immediately following argument (a
		 * still-supported, but no longer encouraged, syntax).
		 */
		char		new_cmd[2];

		new_cmd[0] = my_line[0];
		new_cmd[1] = '\0';

		/* use line for options, because my_line was clobbered above */
		status = exec_command(new_cmd, line + 1, &continue_parse, query_buf, paren_level);

		/*
		 * continue_parse must be relative to my_line for calculation
		 * below
		 */
		continue_parse += my_line - line;

#if 0							/* turned out to be too annoying */
		if (status != CMD_UNKNOWN && isalpha((unsigned char) new_cmd[0]))
			psql_error("Warning: This syntax is deprecated.\n");
#endif
	}

	if (status == CMD_UNKNOWN)
	{
		if (pset.cur_cmd_interactive)
			fprintf(stderr, gettext("Invalid command \\%s. Try \\? for help.\n"), my_line);
		else
			psql_error("invalid command \\%s\n", my_line);
		status = CMD_ERROR;
	}

	if (continue_parse && *continue_parse && *(continue_parse + 1) == '\\')
		continue_parse += 2;

	if (end_of_cmd)
	{
		if (continue_parse)
			*end_of_cmd = line + (continue_parse - my_line);
		else
			*end_of_cmd = line + strlen(line);
	}

	free(my_line);

	return status;
}



static backslashResult
exec_command(const char *cmd,
			 const char *options_string,
			 const char **continue_parse,
			 PQExpBuffer query_buf,
			 volatile int *paren_level)
{
	bool		success = true; /* indicate here if the command ran ok or
								 * failed */
	bool		quiet = QUIET();
	backslashResult status = CMD_SKIP_LINE;
	char	   *string,
			   *string_cpy,
			   *val;

	/*
	 * The 'string' variable will be overwritten to point to the next
	 * token, hence we need an extra pointer so we can free this at the
	 * end.
	 */
	if (options_string)
		string = string_cpy = xstrdup(options_string);
	else
		string = string_cpy = NULL;

	/*
	 * \a -- toggle field alignment This makes little sense but we keep it
	 * around.
	 */
	if (strcmp(cmd, "a") == 0)
	{
		if (pset.popt.topt.format != PRINT_ALIGNED)
			success = do_pset("format", "aligned", &pset.popt, quiet);
		else
			success = do_pset("format", "unaligned", &pset.popt, quiet);
	}

	/* \C -- override table title (formerly change HTML caption) */
	else if (strcmp(cmd, "C") == 0)
	{
		char	   *opt = scan_option(&string, OT_NORMAL, NULL, true);

		success = do_pset("title", opt, &pset.popt, quiet);
		free(opt);
	}

	/*----------
	 * \c or \connect -- connect to new database or as different user
	 *
	 * \c foo bar  connect to db "foo" as user "bar"
	 * \c foo [-]  connect to db "foo" as current user
	 * \c - bar    connect to current db as user "bar"
	 * \c		   connect to default db as default user
	 *----------
	 */
	else if (strcmp(cmd, "c") == 0 || strcmp(cmd, "connect") == 0)
	{
		char	   *opt1,
				   *opt2;
		char		opt1q,
					opt2q;

		/*
		 * Ideally we should treat the arguments as SQL identifiers.  But
		 * for backwards compatibility with 7.2 and older pg_dump files,
		 * we have to take unquoted arguments verbatim (don't downcase
		 * them). For now, double-quoted arguments may be stripped of
		 * double quotes (as if SQL identifiers).  By 7.4 or so, pg_dump
		 * files can be expected to double-quote all mixed-case \connect
		 * arguments, and then we can get rid of OT_SQLIDHACK.
		 */
		opt1 = scan_option(&string, OT_SQLIDHACK, &opt1q, true);
		opt2 = scan_option(&string, OT_SQLIDHACK, &opt2q, true);

		if (opt2)
			/* gave username */
			success = do_connect(!opt1q && (strcmp(opt1, "-") == 0 || strcmp(opt1, "") == 0) ? "" : opt1,
								 !opt2q && (strcmp(opt2, "-") == 0 || strcmp(opt2, "") == 0) ? "" : opt2);
		else if (opt1)
			/* gave database name */
			success = do_connect(!opt1q && (strcmp(opt1, "-") == 0 || strcmp(opt1, "") == 0) ? "" : opt1, "");
		else
			/* connect to default db as default user */
			success = do_connect(NULL, NULL);

		free(opt1);
		free(opt2);
	}

	/* \cd */
	else if (strcmp(cmd, "cd") == 0)
	{
		char	   *opt = scan_option(&string, OT_NORMAL, NULL, true);
		char	   *dir;

		if (opt)
			dir = opt;
		else
		{
#ifndef WIN32
			struct passwd *pw;

			pw = getpwuid(geteuid());
			if (!pw)
			{
				psql_error("could not get home directory: %s\n", strerror(errno));
				exit(EXIT_FAILURE);
			}
			dir = pw->pw_dir;
#else							/* WIN32 */

			/*
			 * On Windows, 'cd' without arguments prints the current
			 * directory, so if someone wants to code this here instead...
			 */
			dir = "/";
#endif   /* WIN32 */
		}

		if (chdir(dir) == -1)
		{
			psql_error("\\%s: could not change directory to \"%s\": %s\n",
					   cmd, dir, strerror(errno));
			success = false;
		}

		if (opt)
			free(opt);
	}

	/* \copy */
	else if (strcasecmp(cmd, "copy") == 0)
	{
		success = do_copy(options_string);
		if (options_string)
			string += strlen(string);
	}

	/* \copyright */
	else if (strcmp(cmd, "copyright") == 0)
		print_copyright();

	/* \d* commands */
	else if (cmd[0] == 'd')
	{
		char	   *pattern;
		bool		show_verbose;

		/* We don't do SQLID reduction on the pattern yet */
		pattern = scan_option(&string, OT_NORMAL, NULL, true);

		show_verbose = strchr(cmd, '+') ? true : false;

		switch (cmd[1])
		{
			case '\0':
			case '+':
				if (pattern)
					success = describeTableDetails(pattern, show_verbose);
				else
					/* standard listing of interesting things */
					success = listTables("tvs", NULL, show_verbose);
				break;
			case 'a':
				success = describeAggregates(pattern, show_verbose);
				break;
			case 'c':
				success = listConversions(pattern);
				break;
			case 'C':
				success = listCasts(pattern);
				break;
			case 'd':
				success = objectDescription(pattern);
				break;
			case 'D':
				success = listDomains(pattern);
				break;
			case 'f':
				success = describeFunctions(pattern, show_verbose);
				break;
			case 'l':
				success = do_lo_list();
				break;
			case 'n':
				success = listSchemas(pattern);
				break;
			case 'o':
				success = describeOperators(pattern);
				break;
			case 'p':
				success = permissionsList(pattern);
				break;
			case 'T':
				success = describeTypes(pattern, show_verbose);
				break;
			case 't':
			case 'v':
			case 'i':
			case 's':
			case 'S':
				success = listTables(&cmd[1], pattern, show_verbose);
				break;
			case 'u':
				success = describeUsers(pattern);
				break;

			default:
				status = CMD_UNKNOWN;
		}

		if (pattern)
			free(pattern);
	}


	/*
	 * \e or \edit -- edit the current query buffer (or a file and make it
	 * the query buffer
	 */
	else if (strcmp(cmd, "e") == 0 || strcmp(cmd, "edit") == 0)
	{
		char	   *fname;

		if (!query_buf)
		{
			psql_error("no query buffer\n");
			status = CMD_ERROR;
		}
		else
		{
			fname = scan_option(&string, OT_NORMAL, NULL, true);
			status = do_edit(fname, query_buf) ? CMD_NEWEDIT : CMD_ERROR;
			free(fname);
		}
	}

	/* \echo and \qecho */
	else if (strcmp(cmd, "echo") == 0 || strcmp(cmd, "qecho") == 0)
	{
		char	   *value;
		char		quoted;
		bool		no_newline = false;
		bool		first = true;
		FILE	   *fout;

		if (strcmp(cmd, "qecho") == 0)
			fout = pset.queryFout;
		else
			fout = stdout;

		while ((value = scan_option(&string, OT_NORMAL, &quoted, false)))
		{
			if (!quoted && strcmp(value, "-n") == 0)
				no_newline = true;
			else
			{
				if (first)
					first = false;
				else
					fputc(' ', fout);
				fputs(value, fout);
			}
			free(value);
		}
		if (!no_newline)
			fputs("\n", fout);
	}

	/* \encoding -- set/show client side encoding */
	else if (strcmp(cmd, "encoding") == 0)
	{
		char	   *encoding = scan_option(&string, OT_NORMAL, NULL, false);

		if (!encoding)
		{
			/* show encoding */
			puts(pg_encoding_to_char(pset.encoding));
		}
		else
		{
			/* set encoding */
			if (PQsetClientEncoding(pset.db, encoding) == -1)
				psql_error("%s: invalid encoding name or conversion procedure not found\n", encoding);
			else
			{
				/* save encoding info into psql internal data */
				pset.encoding = PQclientEncoding(pset.db);
				pset.popt.topt.encoding = pset.encoding;
				SetVariable(pset.vars, "ENCODING",
							pg_encoding_to_char(pset.encoding));
			}
			free(encoding);
		}
	}

	/* \f -- change field separator */
	else if (strcmp(cmd, "f") == 0)
	{
		char	   *fname = scan_option(&string, OT_NORMAL, NULL, false);

		success = do_pset("fieldsep", fname, &pset.popt, quiet);
		free(fname);
	}

	/* \g means send query */
	else if (strcmp(cmd, "g") == 0)
	{
		char	   *fname = scan_option(&string, OT_FILEPIPE, NULL, false);

		if (!fname)
			pset.gfname = NULL;
		else
			pset.gfname = xstrdup(fname);
		free(fname);
		status = CMD_SEND;
	}

	/* help */
	else if (strcmp(cmd, "h") == 0 || strcmp(cmd, "help") == 0)
	{
		helpSQL(options_string ? &options_string[strspn(options_string, " \t\n\r")] : NULL,
				pset.popt.topt.pager);
		/* set pointer to end of line */
		if (string)
			string += strlen(string);
	}

	/* HTML mode */
	else if (strcmp(cmd, "H") == 0 || strcmp(cmd, "html") == 0)
	{
		if (pset.popt.topt.format != PRINT_HTML)
			success = do_pset("format", "html", &pset.popt, quiet);
		else
			success = do_pset("format", "aligned", &pset.popt, quiet);
	}


	/* \i is include file */
	else if (strcmp(cmd, "i") == 0 || strcmp(cmd, "include") == 0)
	{
		char	   *fname = scan_option(&string, OT_NORMAL, NULL, true);

		if (!fname)
		{
			psql_error("\\%s: missing required argument\n", cmd);
			success = false;
		}
		else
		{
			success = (process_file(fname) == EXIT_SUCCESS);
			free(fname);
		}
	}

	/* \l is list databases */
	else if (strcmp(cmd, "l") == 0 || strcmp(cmd, "list") == 0)
		success = listAllDbs(false);
	else if (strcmp(cmd, "l+") == 0 || strcmp(cmd, "list+") == 0)
		success = listAllDbs(true);

	/*
	 * large object things
	 */
	else if (strncmp(cmd, "lo_", 3) == 0)
	{
		char	   *opt1,
				   *opt2;

		opt1 = scan_option(&string, OT_NORMAL, NULL, true);
		opt2 = scan_option(&string, OT_NORMAL, NULL, true);

		if (strcmp(cmd + 3, "export") == 0)
		{
			if (!opt2)
			{
				psql_error("\\%s: missing required argument\n", cmd);
				success = false;
			}
			else
				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
				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 = scan_option(&string, OT_FILEPIPE, NULL, true);

		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(gettext("Query buffer is empty."));
		fflush(stdout);
	}

	/* \pset -- set printing parameters */
	else if (strcmp(cmd, "pset") == 0)
	{
		char	   *opt0 = scan_option(&string, OT_NORMAL, NULL, false);
		char	   *opt1 = scan_option(&string, 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);
		if (paren_level)
			*paren_level = 0;
		if (!quiet)
			puts(gettext("Query buffer reset (cleared)."));
	}

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

		success = saveHistory(fname ? fname : "/dev/tty");

		if (success && !quiet && fname)
			printf(gettext("Wrote history to file \"%s\".\n"), fname);
		free(fname);
	}