| 1 | /*++ |
| 2 | |
| 3 | Copyright (c) Microsoft. All rights reserved. |
| 4 | |
| 5 | Module Name: |
| 6 | |
| 7 | InputChannel.cpp |
| 8 | |
| 9 | Abstract: |
| 10 | |
| 11 | Implementation of InputChannel. |
| 12 | |
| 13 | --*/ |
| 14 | #include "precomp.h" |
| 15 | #include "InputChannel.h" |
| 16 | |
| 17 | #include <wil/resource.h> |
| 18 | |
| 19 | namespace wsl::windows::wslc { |
| 20 | |
| 21 | InputChannel::InputChannel(HANDLE consoleHandle, FILE* readFile) : m_file(readFile) |
| 22 | { |
| 23 | DWORD mode = 0; |
| 24 | if (consoleHandle != INVALID_HANDLE_VALUE && consoleHandle != nullptr && GetConsoleMode(consoleHandle, &mode)) |
| 25 | { |
| 26 | m_consoleHandle = consoleHandle; |
| 27 | } |
| 28 | } |
| 29 | |
| 30 | InputChannel::InputChannel(FILE* readFile, bool interactiveOverride) : |
| 31 | m_file(readFile), m_interactiveOverride(interactiveOverride) |
| 32 | { |
| 33 | } |
| 34 | |
| 35 | bool InputChannel::IsInteractive() const noexcept |
| 36 | { |
| 37 | if (m_consoleHandle != nullptr) |
| 38 | { |
| 39 | DWORD mode = 0; |
| 40 | return GetConsoleMode(m_consoleHandle, &mode) != FALSE; |
| 41 | } |
| 42 | |
| 43 | return m_interactiveOverride; |
| 44 | } |
| 45 | |
| 46 | std::optional<std::wstring> InputChannel::ReadLine(bool mask) const |
| 47 | { |
| 48 | if (m_file == nullptr) |
| 49 | { |
| 50 | return std::nullopt; |
| 51 | } |
| 52 | |
| 53 | // Disable console echo while reading when masking is requested and input is a |
| 54 | // real console. Armed only after echo is actually disabled so the restore is a |
| 55 | // no-op otherwise; runs on every exit path including exceptions. |
| 56 | DWORD previousMode = 0; |
| 57 | bool echoDisabled = false; |
| 58 | auto restoreEcho = wil::scope_exit([&]() { |
| 59 | if (echoDisabled) |
| 60 | { |
| 61 | LOG_IF_WIN32_BOOL_FALSE(SetConsoleMode(m_consoleHandle, previousMode)); |
| 62 | } |
| 63 | }); |
| 64 | |
| 65 | if (mask && m_consoleHandle != nullptr && GetConsoleMode(m_consoleHandle, &previousMode)) |
| 66 | { |
| 67 | // Fail rather than echo a secret if the mode cannot be changed. |
| 68 | THROW_IF_WIN32_BOOL_FALSE(SetConsoleMode(m_consoleHandle, previousMode & ~ENABLE_ECHO_INPUT)); |
| 69 | echoDisabled = true; |
| 70 | } |
| 71 | |
| 72 | std::wstring line; |
| 73 | bool anyRead = false; |
| 74 | for (;;) |
| 75 | { |
| 76 | const wint_t ch = fgetwc(m_file); |
| 77 | if (ch == WEOF) |
| 78 | { |
| 79 | break; |
| 80 | } |
| 81 | |
| 82 | anyRead = true; |
| 83 | if (ch == L'\n') |
| 84 | { |
| 85 | break; |
| 86 | } |
| 87 | |
| 88 | line.push_back(static_cast<wchar_t>(ch)); |
| 89 | } |
| 90 | |
| 91 | if (!anyRead) |
| 92 | { |
| 93 | return std::nullopt; |
| 94 | } |
| 95 | |
| 96 | // The read stops at LF; strip a paired CR so callers get a bare line regardless |
| 97 | // of the input's line-ending convention. |
| 98 | if (!line.empty() && line.back() == L'\r') |
| 99 | { |
| 100 | line.pop_back(); |
| 101 | } |
| 102 | |
| 103 | return line; |
| 104 | } |
| 105 | |
| 106 | } // namespace wsl::windows::wslc |