[PATCH v12 0/1] MR7843: cmd: Implement tab completion for command line entry.

[Joe Souza (＠JoeS209)]

Over the past several weeks I've been working on and off on this.  I didn't track the hours but I'm sure that I've spent 80+ hours on the feature.  I've tested and retested all known scenarios and it seems to be working as expected.

--
  v12: cmd: Implement tab completion for command line entry.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7843

[PATCH v12 1/1] cmd: Implement tab completion for command line entry.

[Joe Souza]

From: Joe Souza <jsouza(a)yahoo.com>

---
 programs/cmd/Makefile.in |   1 +
 programs/cmd/batch.c     |   4 +-
 programs/cmd/lineedit.c  | 431 +++++++++++++++++++++++++++++++++++++++
 programs/cmd/wcmd.h      |   1 +
 4 files changed, 434 insertions(+), 3 deletions(-)
 create mode 100755 programs/cmd/lineedit.c

diff --git a/programs/cmd/Makefile.in b/programs/cmd/Makefile.in
index cca40b84011..0c4c283505d 100644
--- a/programs/cmd/Makefile.in
+++ b/programs/cmd/Makefile.in
@@ -8,5 +8,6 @@ SOURCES = \
 	builtins.c \
 	cmd.rc \
 	directory.c \
+	lineedit.c \
 	wcmd.svg \
 	wcmdmain.c
diff --git a/programs/cmd/batch.c b/programs/cmd/batch.c
index 20ae894dbfd..a06cc7bc495 100644
--- a/programs/cmd/batch.c
+++ b/programs/cmd/batch.c
@@ -227,9 +227,7 @@ WCHAR *WCMD_fgets(WCHAR *buf, DWORD noChars, HANDLE h)
   /* We can't use the native f* functions because of the filename syntax differences
      between DOS and Unix. Also need to lose the LF (or CRLF) from the line. */
 
-  if (VerifyConsoleIoHandle(h) && ReadConsoleW(h, buf, noChars, &charsRead, NULL) && charsRead) {
-      if (!charsRead) return NULL;
-
+  if (VerifyConsoleIoHandle(h) && WCMD_ReadConsole(h, buf, noChars, &charsRead) && charsRead) {
       /* Find first EOL */
       for (i = 0; i < charsRead; i++) {
           if (buf[i] == '\n' || buf[i] == '\r')
diff --git a/programs/cmd/lineedit.c b/programs/cmd/lineedit.c
new file mode 100755
index 00000000000..b514484f2e9
--- /dev/null
+++ b/programs/cmd/lineedit.c
@@ -0,0 +1,431 @@
+/*
+ * CMD - Wine-compatible command line interface - Command line editing
+ *       functions, including tab-completion support
+ *
+ * Copyright (C) 2025 Joe Souza
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#define WIN32_LEAN_AND_MEAN
+
+#include "wcmd.h"
+#include "wine/debug.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(cmd);
+
+typedef struct _SEARCH_CONTEXT
+{
+    HANDLE hSearch;
+    WIN32_FIND_DATAW findData;
+    BOOL haveQuotes;
+    BOOL ignoreTrailingQuote;
+    BOOL isDirSearch;
+    BOOL haveSearchResult;
+    BOOL hadOneMatch;
+    int lastStartQuote;
+    int searchPos;
+    int insertPos;
+} SEARCH_CONTEXT, *PSEARCH_CONTEXT;
+
+
+static BOOL IsDirectoryOperation(const WCHAR *inputBuffer, const ULONG inputBufferLength)
+{
+    int cc = 0;
+    BOOL ret = FALSE;
+
+    while (cc < inputBufferLength && (inputBuffer[cc] == L' ' || inputBuffer[cc] == L'\t')) {
+        cc++;
+    }
+
+    if ((cc + 2 < inputBufferLength && (inputBuffer[cc + 2] == L' ' || inputBuffer[cc + 2] == L'\t')) &&
+        (!_wcsnicmp(&inputBuffer[cc], L"cd", 2) ||
+         !_wcsnicmp(&inputBuffer[cc], L"rd", 2) ||
+         !_wcsnicmp(&inputBuffer[cc], L"md", 2))) {
+
+        ret = TRUE;
+    } else if ((cc + 5 < inputBufferLength && (inputBuffer[cc + 5] == L' ' || inputBuffer[cc + 5] == L'\t')) &&
+        (!_wcsnicmp(&inputBuffer[cc], L"chdir", 5) ||
+         !_wcsnicmp(&inputBuffer[cc], L"rmdir", 5) ||
+         !_wcsnicmp(&inputBuffer[cc], L"mkdir", 5))) {
+
+        ret = TRUE;
+    }
+
+    return ret;
+}
+
+static void ClearConsoleCharacters(const HANDLE hOutput, SHORT cCount, const SHORT width)
+{
+    CONSOLE_SCREEN_BUFFER_INFO csbi;
+    DWORD written;
+    SHORT chars;
+
+    GetConsoleScreenBufferInfo(hOutput, &csbi);
+
+    /* Need to handle clearing multiple lines, in case user resized console window. */
+    while (cCount) {
+        chars = min(width - csbi.dwCursorPosition.X, cCount);
+        FillConsoleOutputCharacterW(hOutput, L' ', chars, csbi.dwCursorPosition, &written);
+        csbi.dwCursorPosition.Y++;      /* Bump to next row. */
+        csbi.dwCursorPosition.X = 0;    /* First column in the row. */
+        cCount -= chars;
+    }
+}
+
+static void SetCursorVisible(const HANDLE hOutput, const BOOL visible)
+{
+    CONSOLE_CURSOR_INFO cursorInfo;
+
+    if (GetConsoleCursorInfo(hOutput, &cursorInfo)) {
+        cursorInfo.bVisible = visible;
+        SetConsoleCursorInfo(hOutput, &cursorInfo);
+    }
+}
+
+static void FindSearchPos(const WCHAR *inputBuffer, int len, PSEARCH_CONTEXT sc)
+{
+    int cc = 0;
+
+    /* Handle spaces in directory names.  Need to quote paths if they contain spaces.
+     * Also, there can be multiple quoted paths on a command line, so find the current
+     * one.
+     */
+    while (cc < len) {
+        if (inputBuffer[cc] == L'\"') {
+            sc->haveQuotes = !sc->haveQuotes;
+            TRACE("Flip haveQuotes, now: %u\n", sc->haveQuotes);
+            if (sc->haveQuotes) {
+                sc->lastStartQuote = cc;
+            }
+        }
+        cc++;
+    }
+
+    /* Special case: If user entered a backslash after quotes, ignore the final quotes. */
+    if (len > 2 && inputBuffer[len-2] == L'\"' && inputBuffer[len-1] == L'\\') {
+        TRACE("Ignore quote before trailing backslash\n");
+        sc->ignoreTrailingQuote = sc->haveQuotes = TRUE;
+    }
+
+    if (sc->haveQuotes) {
+        /* Tab was hit inside a quoted path. Search specification is start of the path. */
+        cc = sc->lastStartQuote + 1;
+    } else {
+        /* Tab was hit outside of a quoted path.  Find the start of this path,
+         * i.e. the first character after the previous spaces and tabs.
+         * This will be the search specification for tab-completion.
+         */
+        cc = len;
+        while (cc > 0 && inputBuffer[cc] != L' ' && inputBuffer[cc] != L'\t') {
+            cc--;
+        }
+        while (cc < len && (inputBuffer[cc] == L' ' || inputBuffer[cc] == L'\t')) {
+            cc++;
+        }
+    }
+
+    sc->searchPos = cc;
+}
+
+static void FindInsertPos(const WCHAR *inputBuffer, int len, PSEARCH_CONTEXT sc)
+{
+    int cc = len;
+
+    /* Handle paths here.  Find last '\\'. */
+    /* Handle spaces in directory names. Look for '\\' on first pass, then quotes on second pass
+     * if '\\' isn't found, and finally whitespace on third pass.
+     */
+    while (cc >= sc->searchPos && inputBuffer[cc] != L'\\') {
+        cc--;
+    }
+
+    if (cc == sc->searchPos && inputBuffer[sc->searchPos] != L'\\') {
+        /* Handle dir "Program Files" */
+        TRACE("haveQuotes: %u, lastStartQuote: %u, curPos: %u\n", sc->haveQuotes, sc->lastStartQuote, len);
+        if (sc->haveQuotes && sc->lastStartQuote) {
+            cc = sc->lastStartQuote;
+        } else {
+            cc = len;
+            while (cc > 0 && inputBuffer[cc] != L' ' && inputBuffer[cc] != L'\t') {
+                cc--;
+            }
+        }
+    }
+
+    if (cc != sc->searchPos || inputBuffer[sc->searchPos] == L'\\') {
+        cc++;
+    }
+
+    sc->insertPos = cc;
+}
+
+static void FindNextMatchingDirectoryEntry(const WCHAR *searchstr, PSEARCH_CONTEXT sc)
+{
+    BOOL search_restart = TRUE;
+
+    while (search_restart) {
+        search_restart = FALSE;
+
+        if (sc->hSearch == INVALID_HANDLE_VALUE) {
+            /* On Windows, the FindExSearchLimitToDirectories specification is merely a suggestion and an
+             * optimization apparently intended for network file systems.
+             */
+            sc->hSearch = FindFirstFileExW(searchstr, FindExInfoStandard, &sc->findData, sc->isDirSearch ? FindExSearchLimitToDirectories : FindExSearchNameMatch, NULL, 0);
+            if (sc->hSearch != INVALID_HANDLE_VALUE) {
+                /* Always skip "." and ".." entries. */
+                if (wcscmp(sc->findData.cFileName, L".") && wcscmp(sc->findData.cFileName, L"..")) {
+                    if (!sc->isDirSearch || sc->findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+                        sc->haveSearchResult = TRUE;
+                    }
+                }
+            }
+        }
+        /* Subsequent search */
+        if (sc->hSearch != INVALID_HANDLE_VALUE && !sc->haveSearchResult) {
+            while (!sc->haveSearchResult && FindNextFileW(sc->hSearch, &sc->findData)) {
+                /* Always skip "." and ".." entries. */
+                if (wcscmp(sc->findData.cFileName, L".") && wcscmp(sc->findData.cFileName, L"..")) {
+                    if (!sc->isDirSearch || sc->findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
+                        sc->haveSearchResult = TRUE;
+                    }
+                }
+            }
+
+            if (!sc->haveSearchResult && sc->hadOneMatch) {
+                sc->hadOneMatch = FALSE;
+                /* Reached the last match, start over. */
+                FindClose(sc->hSearch);
+                sc->hSearch = INVALID_HANDLE_VALUE;
+                search_restart = TRUE;
+            }
+        }
+    }
+
+    if (sc->haveSearchResult) {
+        sc->hadOneMatch = TRUE;
+    }
+}
+
+static void UpdateInputBuffer(WCHAR *inputBuffer, const DWORD inputBufferLength, PSEARCH_CONTEXT sc)
+{
+    BOOL needQuotes = FALSE;
+    int len;
+
+    /* We have found the insert position for the results.  Terminate the string here. */
+    inputBuffer[sc->insertPos] = L'\0';
+
+    needQuotes = wcschr(sc->findData.cFileName, L' ') || sc->findData.cAlternateFileName[0];
+    /* Add starting quotes if needed. */
+    if (needQuotes && !sc->haveQuotes) {
+        len = lstrlenW(inputBuffer);
+        if (len < inputBufferLength - 1) {
+            if (sc->searchPos <= len) {
+                memmove(&inputBuffer[sc->searchPos+1], &inputBuffer[sc->searchPos], (len - sc->searchPos + 1) * sizeof(WCHAR));
+                inputBuffer[sc->searchPos] = L'\"';
+                sc->haveQuotes = TRUE;
+                sc->lastStartQuote = sc->searchPos;
+                sc->insertPos++;
+            }
+        }
+    }
+    lstrcatW(inputBuffer, sc->findData.cFileName);
+    /* Add closing quotes if needed. */
+    if (needQuotes || sc->haveQuotes) {
+        len = lstrlenW(inputBuffer);
+        if (len < inputBufferLength - 1) {
+            inputBuffer[len] = L'\"';
+            inputBuffer[len+1] = L'\0';
+        }
+    }
+}
+
+
+/* Intended as a mostly drop-in replacement for ReadConsole, but with tab-completion support.
+ */
+BOOL WCMD_ReadConsole(const HANDLE hInput, WCHAR *inputBuffer, const DWORD inputBufferLength, LPDWORD numRead)
+{
+    HANDLE hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
+    SEARCH_CONTEXT sc = {0};
+    WCHAR searchstr[MAX_PATH];
+    CONSOLE_SCREEN_BUFFER_INFO startConsoleInfo, lastConsoleInfo;
+    DWORD numWritten;
+    UINT oldCurPos, curPos;
+    BOOL done = FALSE;
+    BOOL ret = FALSE;
+    static int maxLen = 0;  /* Track maximum length in case user fetches a long string from a previous iteration in history. */
+
+    if (hInput == INVALID_HANDLE_VALUE || hOutput == INVALID_HANDLE_VALUE || !inputBuffer || !inputBufferLength) {
+        return FALSE;
+    }
+
+    *inputBuffer = L'\0';
+    curPos = 0;
+
+    sc.hSearch = INVALID_HANDLE_VALUE;
+
+    /* Get starting cursor position and size */
+    GetConsoleScreenBufferInfo(hOutput, &startConsoleInfo);
+    lastConsoleInfo = startConsoleInfo;
+
+    while (!done) {
+        CONSOLE_READCONSOLE_CONTROL inputControl;
+        int len;
+
+        len = lstrlenW(inputBuffer);
+
+        /* Update current input display in console */
+        SetCursorVisible(hOutput, FALSE);
+        SetConsoleCursorPosition(hOutput, startConsoleInfo.dwCursorPosition);
+        WriteConsoleW(hOutput, inputBuffer, len, &numWritten, NULL);
+        if (maxLen > len) {
+            ClearConsoleCharacters(hOutput, maxLen - len, lastConsoleInfo.dwSize.X); /* width at time of last console update */
+        }
+        SetCursorVisible(hOutput, TRUE);
+
+        /* Remember current dimensions in case user resizes console window. */
+        GetConsoleScreenBufferInfo(hOutput, &lastConsoleInfo);
+
+        inputControl.nLength = sizeof(inputControl);
+        inputControl.nInitialChars = len;
+        /* FIXME: 0x1B (ESC) does not work in the Linux console.  Works in the Wine console, though. */
+        inputControl.dwCtrlWakeupMask = (1 << '\t') | (1 << 0x1B);
+        /* FIXME: In the Windows SDK this is called dwControlKeyState */
+        inputControl.dwConsoleKeyState = 0;
+
+        /* Allow room for NULL terminator. inputBufferLength is at least 1 due to check above. */
+        ret = ReadConsoleW(hInput, inputBuffer, inputBufferLength - 1, numRead, &inputControl);
+
+        if (ret) {
+            inputBuffer[*numRead] = L'\0';
+            TRACE("ReadConsole: [%lu][%s]\n", *numRead, wine_dbgstr_w(inputBuffer));
+            len = *numRead;
+            if (len > maxLen) {
+                maxLen = len;
+            }
+            oldCurPos = curPos;
+            curPos = 0;
+            while (curPos < len &&
+                   inputBuffer[curPos] != L'\t' &&
+                   inputBuffer[curPos] != L'\x1B'
+                   ) {
+
+                curPos++;
+            }
+            /* curPos is often numRead - 1, but not always, as in the case where history is retrieved
+             * and then user backspaces to somewhere mid-string and then hits Tab.
+             */
+            TRACE("numRead: %lu, curPos: %u\n", *numRead, curPos);
+
+            switch (inputBuffer[curPos]) {
+            case L'\t':
+                TRACE("TAB: [%s]\n", wine_dbgstr_w(inputBuffer));
+                inputBuffer[curPos] = L'\0';
+                len = curPos;
+                sc.haveSearchResult = FALSE;
+
+                /* See if we need to reset an existing search. */
+                if (sc.hSearch != INVALID_HANDLE_VALUE) {
+                    /* If tab key was hit at a different location than last time */
+                    if (curPos != oldCurPos) {
+                        TRACE("***** Reset search, tab hit at different location, curPos: %u, oldCurPos: %u\n", curPos, oldCurPos);
+                        FindClose(sc.hSearch);
+                        sc.hSearch = INVALID_HANDLE_VALUE;
+                    }
+                }
+
+                /* If new search */
+                if (sc.hSearch == INVALID_HANDLE_VALUE) {
+                    sc.lastStartQuote = 0;
+                    sc.haveQuotes = FALSE;
+                    sc.ignoreTrailingQuote = FALSE;
+                    sc.searchPos = 0;
+                    sc.insertPos = 0;
+
+                    FindSearchPos(inputBuffer, curPos, &sc);
+
+                    /* Build search string. */
+                    lstrcpynW(searchstr, &inputBuffer[sc.searchPos], ARRAY_SIZE(searchstr) - 2);
+                    if (sc.ignoreTrailingQuote) {
+                        len = lstrlenW(searchstr);
+                        searchstr[len-2] = L'\\';
+                        searchstr[len-1] = L'\0';
+                    }
+                    lstrcatW(searchstr, L"*");
+                    TRACE("New search: [%s]\n", wine_dbgstr_w(searchstr));
+
+                    sc.isDirSearch = IsDirectoryOperation(inputBuffer, inputBufferLength);
+                }
+
+                FindNextMatchingDirectoryEntry(searchstr, &sc);
+
+                if (sc.haveSearchResult) {
+                    /* If this is our first time through here for this search, we need to find the insert position
+                     * for the results.  Note that this is very likely not the same location as the search position.
+                     */
+                    if (!sc.insertPos) {
+                        /* If user entered a backslash after quotes, remove the quotes. */
+                        if (curPos > 2 && inputBuffer[curPos-2] == L'\"' && inputBuffer[curPos-1] == L'\\') {
+                            TRACE("Remove quote before trailing backslash\n");
+                            inputBuffer[curPos-2] = L'\\';
+                            inputBuffer[curPos-1] = L'\0';
+                            curPos--;
+                        }
+
+                        FindInsertPos(inputBuffer, curPos, &sc);
+                    }
+
+                    /* Copy search results to input buffer. */
+                    UpdateInputBuffer(inputBuffer, inputBufferLength, &sc);
+
+                    /* Update cursor position to end of buffer. */
+                    curPos = lstrlenW(inputBuffer);
+                    if (curPos > maxLen) {
+                        maxLen = curPos;
+                    }
+                }
+                break;
+
+            case L'\x1B': /* ESC */
+                /* FIXME: We shouldn't need to handle the ESC key in this code.  ReadConsole on Windows will clear the text
+                 * from the screen and the buffer, but Wine does not, instead emitting '^]' at the console.
+                 */
+                TRACE("ESC: [%s], len: %u, maxLen: %u\n", wine_dbgstr_w(inputBuffer), len, maxLen);
+                /* Clear buffer.  Screen will be cleaned at top of loop. */
+                inputBuffer[0] = L'\0';
+                curPos = 0;
+                break;
+
+            default:
+                TRACE("RETURN: [%s]\n", wine_dbgstr_w(inputBuffer));
+                done = TRUE;
+                break;
+            }
+
+        } else {
+            /* ReadConsole failed */
+            done = TRUE;
+        }
+    }
+
+    /* Close any existing search before exiting. */
+    if (sc.hSearch != INVALID_HANDLE_VALUE) {
+        FindClose(sc.hSearch);
+        sc.hSearch = INVALID_HANDLE_VALUE;
+    }
+
+    return ret;
+}
+
diff --git a/programs/cmd/wcmd.h b/programs/cmd/wcmd.h
index d4adc7fd7c8..4f8486bbc9e 100644
--- a/programs/cmd/wcmd.h
+++ b/programs/cmd/wcmd.h
@@ -212,6 +212,7 @@ WCHAR *WCMD_LoadMessage(UINT id);
 WCHAR *WCMD_strsubstW(WCHAR *start, const WCHAR* next, const WCHAR* insert, int len);
 RETURN_CODE WCMD_wait_for_input(HANDLE hIn);
 BOOL WCMD_ReadFile(const HANDLE hIn, WCHAR *intoBuf, const DWORD maxChars, LPDWORD charsRead);
+BOOL WCMD_ReadConsole(const HANDLE hInput, WCHAR *inputBuffer, const DWORD inputBufferLength, LPDWORD numRead);
 
 enum read_parse_line {RPL_SUCCESS, RPL_EOF, RPL_SYNTAXERROR};
 enum read_parse_line WCMD_ReadAndParseLine(const WCHAR *initialcmd, CMD_NODE **output);
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/7843

[Joe Souza (＠JoeS209)]

Latest changes pushed.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7843#note_101606

[Joe Souza (＠JoeS209)]

On Tue Apr 22 00:18:51 2025 +0000, Joe Souza wrote:
> Thanks, will fix.
> Note that this is addressed by reducing the length passed to ReadConsoleW by 1, to guarantee room for the null terminator.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7843#note_101607