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/***
*cgetws.c - buffered keyboard input** Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.**Purpose:* defines _cgetws() - read a string directly from console**Revision History:* 04-19-00 GB Module created based on cgets.* 05-17-00 GB Use ERROR_CALL_NOT_IMPLEMENTED for existance of W API* 04-29-02 GB Added try-finally arounds lock-unlock.********************************************************************************/#include <cruntime.h>
#include <oscalls.h>
#include <mtdll.h>
#include <conio.h>
#include <stdlib.h>
#include <internal.h>
#define BUF_MAX_LEN 64
extern intptr_t _coninpfh;static int bUseW = 2;
/***
*wchar_t *_cgetws(string) - read string from console**Purpose:* Reads a string from the console via ReadConsoleW on a cooked console* handle. string[0] must contain the maximum length of the* string. Returns pointer to str[2].** NOTE: _cgetsw() does NOT check the pushback character buffer (i.e.,* _chbuf). Thus, _cgetws() will not return any character that is* pushed back by the _ungetwch() call.**Entry:* char *string - place to store read string, str[0] = max length.**Exit:* returns pointer to str[2], where the string starts.* returns NULL if error occurs**Exceptions:********************************************************************************/
wchar_t * __cdecl _cgetws ( wchar_t *string ){ ULONG oldstate; ULONG num_read; wchar_t *result;
string[1] = 0; /* no chars read yet */ result = &string[2];
/*
* _coninpfh, the handle to the console input, is created the first * time that either _getch() or _cgets() or _kbhit() is called. */
_mlock(_CONIO_LOCK); /* lock the console */ __TRY
if ( _coninpfh == -2 ) __initconin();
if ( _coninpfh == -1 ) { result=NULL; } else {
GetConsoleMode( (HANDLE)_coninpfh, &oldstate ); SetConsoleMode( (HANDLE)_coninpfh, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT | ENABLE_ECHO_INPUT ); // First try usual way just as _cgets
if ( bUseW) { if ( !ReadConsoleW( (HANDLE)_coninpfh, (LPVOID)result, (unsigned)string[0], &num_read, NULL ) ) { result = NULL; if ( bUseW == 2 && GetLastError() == ERROR_CALL_NOT_IMPLEMENTED) bUseW = FALSE; } else bUseW = TRUE; if ( result != NULL ) { /* set length of string and null terminate it */ if (string[num_read] == L'\r') { string[1] = (wchar_t)(num_read - 2); string[num_read] = L'\0'; } else if ( (num_read == (ULONG)string[0]) && (string[num_read + 1] == L'\r') ) { /* special case 1 - \r\n straddles the boundary */ string[1] = (wchar_t)(num_read -1); string[1 + num_read] = L'\0'; } else if ( (num_read == 1) && (string[2] == L'\n') ) { /* special case 2 - read a single '\n'*/ string[1] = string[2] = L'\0'; } else { string[1] = (wchar_t)num_read; string[2 + num_read] = L'\0'; } } } // If ReadConsoleW is not present, use ReadConsoleA and then convert
// to Wide Char.
if ( !bUseW) { static char AStr[BUF_MAX_LEN +1]; static int in_buff = 0, was_buff_full = 0; unsigned int Copy, Sz, consoleCP; unsigned int last_read = 0, i; consoleCP = GetConsoleCP(); do { if (!in_buff) { if ( !ReadConsoleA( (HANDLE)_coninpfh, (LPVOID)AStr, BUF_MAX_LEN, &num_read, NULL) ) result = NULL; if (result != NULL) { if (AStr[num_read -2] == '\r') AStr[num_read -2] = '\0'; else if (num_read == sizeof(AStr) && AStr[num_read -1] == '\r') AStr[num_read -1] = '\0'; else if (num_read == 1 && string[0] == '\n') AStr[0] = '\0'; else AStr[num_read] = '\0'; } } for ( i = 0; AStr[i] != '\0' && i < (BUF_MAX_LEN) && last_read < (unsigned)string[0]; i += Sz) { // Check if this character is lead byte. If yes, the size
// of this character is 2. Else 1.
if ( IsDBCSLeadByteEx( GetConsoleCP(), AStr[i])) Sz = 2; else Sz = 1; if ( (Copy = MultiByteToWideChar( consoleCP, MB_PRECOMPOSED | MB_ERR_INVALID_CHARS, &AStr[i], Sz, &string[2+last_read], string[0] - last_read))) { last_read += Copy; } } // Check if this conversion was from buffer. If yes, was
// buffer fully filled when it was first read using
// ReadConsoleA. If the buffer not fully filled, we don't need
// to read more from buffer. This is necessary to make it
// behave same as if we are reading using ReadConsoleW.
if ( in_buff && i == strlen(AStr)) { in_buff = 0; if ( was_buff_full) { was_buff_full = 0; continue; } else { break; } } else if ( i < (BUF_MAX_LEN)) break; } while (last_read < (unsigned)string[0]); // We save the buffer to be used again.
if ( i < strlen(AStr)) { in_buff = 1; if ( strlen(AStr) == (BUF_MAX_LEN)) was_buff_full = 1; memmove(AStr, &AStr[i], BUF_MAX_LEN +1 - i); } string[2+last_read] = '\0'; string[1] = (wchar_t)last_read; }
SetConsoleMode( (HANDLE)_coninpfh, oldstate ); } __FINALLY _munlock(_CONIO_LOCK); /* unlock the console */ __END_TRY_FINALLY
return result;}
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