/*
 * psql - the PostgreSQL interactive terminal
 *
 * Copyright 2000 by PostgreSQL Global Development Group
 *
 * $Header: /home/projects/pgsql/cvsroot/pgsql/src/bin/psql/help.c,v 1.31 2000/05/26 15:47:18 momjian Exp $
 */
#include "postgres.h"
#include "help.h"

#include <signal.h>
#include <errno.h>

#ifndef WIN32
#include <sys/ioctl.h>			/* for ioctl() */
#ifdef HAVE_PWD_H
#include <pwd.h>				/* for getpwuid() */
#endif
#include <sys/types.h>			/* (ditto) */
#include <unistd.h>				/* for getuid() */
#else
#include <win32.h>
#endif

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

#include "settings.h"
#include "common.h"
#include "sql_help.h"

/*
 * PLEASE:
 * If you change something in this file, also make the same changes
 * in the DocBook documentation, file ref/psql-ref.sgml. If you don't
 * know how to do it, please find someone who can help you.
 */


/*
 * usage
 *
 * print out command line arguments
 */
#define ON(var) (var ? "on" : "off")

void
usage(void)
{
	const char *env;
	const char *user;

#ifndef WIN32
	struct passwd *pw = NULL;

#endif

	/* Find default user, in case we need it. */
	user = getenv("USER");
	if (!user)
	{
#ifndef WIN32
		pw = getpwuid(geteuid());
		if (pw)
			user = pw->pw_name;
		else
		{
			psql_error("could not get current user name: %s\n", strerror(errno));
			exit(EXIT_FAILURE);
		}
#else
		user = "?";
#endif
	}

/* If this " is the start of the string then it ought to end there to fit in 80 columns >> " */
	puts("This is psql, the PostgreSQL interactive terminal.\n");
	puts("Usage:");
	puts("  psql [options] [dbname [username]]\n");
	puts("Options:");
	puts("  -a              Echo all input from script");
	puts("  -A              Unaligned table output mode (-P format=unaligned)");
	puts("  -c <query>      Run only single query (or slash command) and exit");

	/* Display default database */
	env = getenv("PGDATABASE");
	if (!env)
		env = user;
	printf("  -d <dbname>     Specify database name to connect to (default: %s)\n", env);

	puts("  -e              Echo queries sent to backend");
	puts("  -E              Display queries that internal commands generate");
	puts("  -f <filename>   Execute queries from file, then exit");
	puts("  -F <string>     Set field separator (default: \"" DEFAULT_FIELD_SEP "\") (-P fieldsep=)");

	/* Display default host */
	env = getenv("PGHOST");
	printf("  -h <host>       Specify database server host (default: ");
	if (env)
		fputs(env, stdout);
	else
		fputs("domain socket", stdout);
	puts(")");

	puts("  -H              HTML table output mode (-P format=html)");
	puts("  -l              List available databases, then exit");
	puts("  -n              Disable readline");
	puts("  -o <filename>   Send query output to filename (or |pipe)");

	/* Display default port */
	env = getenv("PGPORT");
	printf("  -p <port>       Specify database server port (default: %s)\n",
		   env ? env : "hardwired");

	puts("  -P var[=arg]    Set printing option 'var' to 'arg' (see \\pset command)");
	puts("  -q              Run quietly (no messages, only query output)");
	puts("  -R <string>     Set record separator (default: newline) (-P recordsep=)");
	puts("  -s              Single step mode (confirm each query)");
	puts("  -S              Single line mode (newline terminates query)");
	puts("  -t              Print rows only (-P tuples_only)");
	puts("  -T text         Set HTML table tag options (width, border) (-P tableattr=)");

	/* Display default user */
	env = getenv("PGUSER");
	if (!env)
		env = user;
	printf("  -U <username>   Specify database username (default: %s)\n", env);

	puts("  -v name=val     Set psql variable 'name' to 'value'");
	puts("  -V              Show version information and exit");
	puts("  -W              Prompt for password (should happen automatically)");
	puts("  -x              Turn on expanded table output (-P expanded)");
	puts("  -X              Do not read startup file (~/.psqlrc)");

	puts("\nFor more information, type \"\\?\" (for internal commands) or \"\\help\"");
	puts("(for SQL commands) from within psql, or consult the psql section in");
	puts("the PostgreSQL manual, which accompanies the distribution and is also");
	puts("available at <http://www.postgresql.org>.");
	puts("Report bugs to <pgsql-bugs@postgresql.org>.");

#ifndef WIN32
	if (pw)
		free(pw);
#endif
}



/*
 * slashUsage
 *
 * print out help for the backslash commands
 */

#ifndef TIOCGWINSZ
struct winsize
{
	int			ws_row;
	int			ws_col;
};

#endif

void
slashUsage(void)
{
	bool		usePipe = false;
	const char *pagerenv;
	FILE	   *fout;
	struct winsize screen_size;

#ifdef TIOCGWINSZ
	if (pset.notty == 0 &&
		(ioctl(fileno(stdout), TIOCGWINSZ, &screen_size) == -1 ||
		 screen_size.ws_col == 0 ||
		 screen_size.ws_row == 0))
	{
#endif
		screen_size.ws_row = 24;
		screen_size.ws_col = 80;
#ifdef TIOCGWINSZ
	}
#endif

	if (pset.notty == 0 &&
		(pagerenv = getenv("PAGER")) &&
		(pagerenv[0] != '\0') &&
		screen_size.ws_row <= 39 &&
		(fout = popen(pagerenv, "w")))
	{
		usePipe = true;
#ifndef WIN32
		pqsignal(SIGPIPE, SIG_IGN);
#endif
	}
	else
		fout = stdout;

	/* if you add/remove a line here, change the row test above */
	fprintf(fout, " \\a             toggle between unaligned and aligned mode\n");
	fprintf(fout, " \\c[onnect] [dbname|- [user]]\n"
			"                connect to new database (currently '%s')\n", PQdb(pset.db));
	fprintf(fout, " \\C <title>     table title\n");
	fprintf(fout, " \\copy ...      perform SQL COPY with data stream to the client machine\n");
	fprintf(fout, " \\copyright     show PostgreSQL usage and distribution terms\n");
	fprintf(fout, " \\d <table>     describe table (or view, index, sequence)\n");
	fprintf(fout, " \\d{t|i|s|v}    list tables/indices/sequences/views\n");
	fprintf(fout, " \\d{p|S|l}      list permissions/system tables/lobjects\n");
	fprintf(fout, " \\da            list aggregates\n");
	fprintf(fout, " \\dd [object]   list comment for table, type, function, or operator\n");
	fprintf(fout, " \\df            list functions\n");
	fprintf(fout, " \\do            list operators\n");
	fprintf(fout, " \\dT            list data types\n");
	fprintf(fout, " \\e [file]      edit the current query buffer or [file] with external editor\n");
	fprintf(fout, " \\echo <text>   write text to stdout\n");
	fprintf(fout, " \\encoding <encoding>  set client encoding\n");
	fprintf(fout, " \\f <sep>       change field separator\n");
	fprintf(fout, " \\g [file]      send query to backend (and results in [file] or |pipe)\n");
	fprintf(fout, " \\h [cmd]       help on syntax of sql commands, * for all commands\n");
	fprintf(fout, " \\H             toggle HTML mode (currently %s)\n",
			ON(pset.popt.topt.format == PRINT_HTML));
	fprintf(fout, " \\i <file>      read and execute queries from <file>\n");
	fprintf(fout, " \\l             list all databases\n");
	fprintf(fout, " \\lo_export, \\lo_import, \\lo_list, \\lo_unlink\n"
			"                large object operations\n");
	fprintf(fout, " \\o [file]      send all query results to [file], or |pipe\n");
	fprintf(fout, " \\p             show the content of the current query buffer\n");
	fprintf(fout, " \\pset <opt>    set table output  <opt> = {format|border|expanded|fieldsep|\n"
			"                null|recordsep|tuples_only|title|tableattr|pager}\n");
	fprintf(fout, " \\q             quit psql\n");
	fprintf(fout, " \\qecho <text>  write text to query output stream (see \\o)\n");
	fprintf(fout, " \\r             reset (clear) the query buffer\n");
	fprintf(fout, " \\s [file]      print history or save it in [file]\n");
	fprintf(fout, " \\set <var> <value>  set internal variable\n");
	fprintf(fout, " \\t             show only rows (currently %s)\n", ON(pset.popt.topt.tuples_only));
	fprintf(fout, " \\T <tags>      HTML table tags\n");
	fprintf(fout, " \\unset <var>   unset (delete) internal variable\n");
	fprintf(fout, " \\w <file>      write current query buffer to a <file>\n");
	fprintf(fout, " \\x             toggle expanded output (currently %s)\n", ON(pset.popt.topt.expanded));
	fprintf(fout, " \\z             list table access permissions\n");
	fprintf(fout, " \\! [cmd]       shell escape or command\n");

	if (usePipe)
	{
		pclose(fout);
#ifndef WIN32
		pqsignal(SIGPIPE, SIG_DFL);
#endif
	}
}



/*
 * helpSQL -- help with SQL commands
 *
 */
void
helpSQL(const char *topic)
{
#define VALUE_OR_NULL(a) ((a) ? (a) : "")

	if (!topic || strlen(topic) == 0)
	{
		int			i;
		int			items_per_column = (QL_HELP_COUNT + 2) / 3;

		puts("Available help:");

		for (i = 0; i < items_per_column; i++)
		{
			printf("  %-26s%-26s",
					VALUE_OR_NULL(QL_HELP[i].cmd),
					VALUE_OR_NULL(QL_HELP[i + items_per_column].cmd));
			if (i + 2 * items_per_column < QL_HELP_COUNT)
				printf("%-26s",
					VALUE_OR_NULL(QL_HELP[i + 2 * items_per_column].cmd));
			fputc('\n', stdout);
		}
	}

	else
	{
		int			i;
		bool		help_found = false;
		size_t      len;

		/* don't care about trailing spaces */
		len = strlen(topic);
		while (topic[len-1] == ' ')
			len--;

		for (i = 0; QL_HELP[i].cmd; i++)
		{
			if (strncasecmp(topic, QL_HELP[i].cmd, len) == 0 ||
				strcmp(topic, "*") == 0)
			{
				help_found = true;
				printf("Command:     %s\n"
					   "Description: %s\n"
					   "Syntax:\n%s\n\n",
					 QL_HELP[i].cmd, QL_HELP[i].help, QL_HELP[i].syntax);
				/* If we have an exact match, exit.  Fixes \h SELECT */
				if (strcasecmp(topic, QL_HELP[i].cmd) == 0)
					break;
			}
		}

		if (!help_found)
			printf("No help available for '%-.*s'.\nTry \\h with no arguments to see available help.\n", (int)len, topic);
	}
}



void
print_copyright(void)
{
	puts(
		 "PostgreSQL Data Base Management System\n\n"
		 "Portions Copyright (c) 1996-2000, PostgreSQL, Inc\n\n"
		 "This software is based on Postgres95, formerly known as Postgres, which\n"
		 "contains the following notice:\n\n"
		 "Portions Copyright(c) 1994 - 7 Regents of the University of California\n\n"
		 "Permission to use, copy, modify, and distribute this software and its\n"
		 "documentation for any purpose, without fee, and without a written agreement\n"
		 "is hereby granted, provided that the above copyright notice and this paragraph\n"
		 "and the following two paragraphs appear in all copies.\n\n"
		 "IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR\n"
		 "DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST\n"
		 "PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF\n"
		 "THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH\n"
		 "DAMAGE.\n\n"
		 "THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,\n"
		 "BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A\n"
		 "PARTICULAR PURPOSE.THE SOFTWARE PROVIDED HEREUNDER IS ON AN \"AS IS\" BASIS,\n"
		 "AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,\n"
		 "SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
	);
}
