sprompt.cpp

/*-------------------------------------------------------------------------
 *
 * sprompt.c
 *	  simple_prompt() routine
 *
 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/port/sprompt.c,v 1.18 2006/10/04 00:30:14 momjian Exp $
 *
 *-------------------------------------------------------------------------
 *
 * PostgreSQL Database Management System
 * (formerly known as Postgres, then as Postgres95)
 *
 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 *
 * Portions Copyright (c) 1994, The Regents of the University of California
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without a written agreement
 * is hereby granted, provided that the above copyright notice and this
 * paragraph and the following two paragraphs appear in all copies.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
 * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
 * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 */


/*
 * simple_prompt
 *
 * Generalized function especially intended for reading in usernames and
 * password interactively. Reads from /dev/tty or stdin/stderr.
 *
 * prompt:		The prompt to print
 * maxlen:		How many characters to accept
 * echo:		Set to false if you want to hide what is entered (for passwords)
 *
 * Returns a malloc()'ed string with the input (w/o trailing newline).
 */

#define DEVTTY "/dev/tty"

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <unistd.h>

#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif

#ifdef _WIN32
#include <windows.h>
#endif

char *
simple_prompt(const char *prompt, int maxlen, int echo)
{
	int			length;
	char	   *destination;
	FILE	   *termin,
			   *termout;

#ifdef HAVE_TERMIOS_H
	struct termios t_orig,
				t;
#else
#ifdef _WIN32
	HANDLE		t = NULL;
	LPDWORD		t_orig = NULL;
#endif
#endif

	destination = (char *) malloc(maxlen + 1);
	if (!destination)
		return NULL;

	/*
	 * Do not try to collapse these into one "w+" mode file. Doesn't work on
	 * some platforms (eg, HPUX 10.20).
	 */
	termin = fopen(DEVTTY, "r");
	termout = fopen(DEVTTY, "w");
	if (!termin || !termout
#ifdef _WIN32
	/* See DEVTTY comment for msys */
		|| (getenv("OSTYPE") && strcmp(getenv("OSTYPE"), "msys") == 0)
#endif
		)
	{
		if (termin)
			fclose(termin);
		if (termout)
			fclose(termout);
		termin = stdin;
		termout = stderr;
	}

#ifdef HAVE_TERMIOS_H
	if (!echo)
	{
		tcgetattr(fileno(termin), &t);
		t_orig = t;
		t.c_lflag &= ~ECHO;
		tcsetattr(fileno(termin), TCSAFLUSH, &t);
	}
#else
#ifdef _WIN32
	if (!echo)
	{
		/* get a new handle to turn echo off */
		t_orig = (LPDWORD) malloc(sizeof(DWORD));
		t = GetStdHandle(STD_INPUT_HANDLE);

		/* save the old configuration first */
		GetConsoleMode(t, t_orig);

		/* set to the new mode */
		SetConsoleMode(t, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
	}
#endif
#endif

	if (prompt)
	{
		fputs(prompt, termout);
		fflush(termout);
	}

	if (fgets(destination, maxlen + 1, termin) == NULL)
		destination[0] = '\0';

	length = strlen(destination);
	if (length > 0 && destination[length - 1] != '\n')
	{
		/* eat rest of the line */
		char		buf[128];
		int			buflen;

		do
		{
			if (fgets(buf, sizeof(buf), termin) == NULL)
				break;
			buflen = strlen(buf);
		} while (buflen > 0 && buf[buflen - 1] != '\n');
	}

	if (length > 0 && destination[length - 1] == '\n')
		/* remove trailing newline */
		destination[length - 1] = '\0';

#ifdef HAVE_TERMIOS_H
	if (!echo)
	{
		tcsetattr(fileno(termin), TCSAFLUSH, &t_orig);
		fputs("\n", termout);
		fflush(termout);
	}
#else
#ifdef _WIN32
	if (!echo)
	{
		/* reset to the original console mode */
		SetConsoleMode(t, *t_orig);
		fputs("\n", termout);
		fflush(termout);
		free(t_orig);
	}
#endif
#endif

	if (termin != stdin)
	{
		fclose(termin);
		fclose(termout);
	}

	return destination;
}