YugabyteDB (2.13.1.0-b60, 21121d69985fbf76aa6958d8f04a9bfa936293b5)

/*-------------------------------------------------------------------------

 *

 * sprompt.c

 *    simple_prompt() routine

 *

 * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group

 * Portions Copyright (c) 1994, Regents of the University of California

 *

 *

 * IDENTIFICATION

 *    src/port/sprompt.c

 *

 *-------------------------------------------------------------------------

 */

#include "c.h"

#ifdef HAVE_TERMIOS_H

#include <termios.h>

#endif

/*

 * simple_prompt

 *

 * Generalized function especially intended for reading in usernames and

 * passwords interactively.  Reads from /dev/tty or stdin/stderr.

 *

 * prompt:    The prompt to print, or NULL if none (automatically localized)

 * destination: buffer in which to store result

 * destlen:   allocated length of destination

 * echo:    Set to false if you want to hide what is entered (for passwords)

 *

 * The input (without trailing newline) is returned in the destination buffer,

 * with a '\0' appended.

 */

void

simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)

{

  int     length;

  FILE     *termin,

         *termout;

#if defined(HAVE_TERMIOS_H)

  struct termios t_orig,

        t;

#elif defined(WIN32)

  HANDLE    t = NULL;

  DWORD   t_orig = 0;

#endif

#ifdef WIN32

  /*

   * A Windows console has an "input code page" and an "output code page";

   * these usually match each other, but they rarely match the "Windows ANSI

   * code page" defined at system boot and expected of "char *" arguments to

   * Windows API functions.  The Microsoft CRT write() implementation

   * automatically converts text between these code pages when writing to a

   * console.  To identify such file descriptors, it calls GetConsoleMode()

   * on the underlying HANDLE, which in turn requires GENERIC_READ access on

   * the HANDLE.  Opening termout in mode "w+" allows that detection to

   * succeed.  Otherwise, write() would not recognize the descriptor as a

   * console, and non-ASCII characters would display incorrectly.

   *

   * XXX fgets() still receives text in the console's input code page.  This

   * makes non-ASCII credentials unportable.

   *

   * Unintuitively, we also open termin in mode "w+", even though we only

   * read it; that's needed for SetConsoleMode() to succeed.

   */

  termin = fopen("CONIN$", "w+");

  termout = fopen("CONOUT$", "w+");

#else

  /*

   * Do not try to collapse these into one "w+" mode file. Doesn't work on

   * some platforms (eg, HPUX 10.20).

   */

  termin = fopen("/dev/tty", "r");

  termout = fopen("/dev/tty", "w");

#endif

  if (!termin || !termout

#ifdef WIN32

  /*

   * Direct console I/O does not work from the MSYS 1.0.10 console.  Writes

   * reach nowhere user-visible; reads block indefinitely.  XXX This affects

   * most Windows terminal environments, including rxvt, mintty, Cygwin

   * xterm, Cygwin sshd, and PowerShell ISE.  Switch to a more-generic test.

   */

    || (getenv("OSTYPE") && strcmp(getenv("OSTYPE"), "msys") == 0)

#endif

    )

  {

    if (termin)

      fclose(termin);

    if (termout)

      fclose(termout);

    termin = stdin;

    termout = stderr;

  }

  if (!echo)

  {

#if defined(HAVE_TERMIOS_H)

    /* disable echo via tcgetattr/tcsetattr */

    tcgetattr(fileno(termin), &t);

    t_orig = t;

    t.c_lflag &= ~ECHO;

    tcsetattr(fileno(termin), TCSAFLUSH, &t);

#elif defined(WIN32)

    /* need the file's HANDLE to turn echo off */

    t = (HANDLE) _get_osfhandle(_fileno(termin));

    /* save the old configuration first */

    GetConsoleMode(t, &t_orig);

    /* set to the new mode */

    SetConsoleMode(t, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);

#endif

  }

  if (prompt)

  {

    fputs(_(prompt), termout);

    fflush(termout);

  }

  if (fgets(destination, destlen, 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';

  if (!echo)

  {

    /* restore previous echo behavior, then echo \n */

#if defined(HAVE_TERMIOS_H)

    tcsetattr(fileno(termin), TCSAFLUSH, &t_orig);

    fputs("\n", termout);

    fflush(termout);

#elif defined(WIN32)

    SetConsoleMode(t, t_orig);

    fputs("\n", termout);

    fflush(termout);

#endif

  }

  if (termin != stdin)

  {

    fclose(termin);

    fclose(termout);

  }

}