batch.c

/*
 * CMD - Wine-compatible command line interface - batch interface.
 *
 * Copyright (C) 1999 D A Pickles
 * Copyright (C) 2007 J Edmeades
 *
 * 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
 */

#include "wcmd.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(cmd);

static RETURN_CODE WCMD_batch_main_loop(void)
{
    RETURN_CODE return_code = NO_ERROR;
    enum read_parse_line rpl;
    CMD_NODE *node;

    /* Work through the file line by line until an exit is called. */
    while ((rpl = WCMD_ReadAndParseLine(&node)) != RPL_EOF)
    {
        switch (rpl)
        {
        case RPL_EOF: break; /* never reached; get rid of warning */
        case RPL_SUCCESS:
            if (node)
            {
                return_code = node_execute(node);
                node_dispose_tree(node);
            }
            break;
        case RPL_SYNTAXERROR:
            return_code = RETURN_CODE_SYNTAX_ERROR;
            break;
        }
    }

    /* If there are outstanding setlocal's to the current context, unwind them. */
    if (WCMD_is_in_context(NULL))
        while (WCMD_endlocal() == NO_ERROR) {}

    return return_code;
}

static struct batch_file *find_or_alloc_batch_file(const WCHAR *file)
{
    struct batch_file *batchfile;
    struct batch_context *ctx;
    HANDLE h;
    unsigned int i;

    if (!file) return NULL;
    for (ctx = context; ctx; ctx = ctx->prev_context)
    {
        if (ctx->batch_file && !wcscmp(ctx->batch_file->path_name, file))
            return ctx->batch_file;
    }
    batchfile = xalloc(sizeof(*batchfile));
    batchfile->ref_count = 0;
    batchfile->path_name = xstrdupW(file);

    h = CreateFileW(file, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
                    NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (h == INVALID_HANDLE_VALUE || !GetFileTime(h, NULL, NULL, &batchfile->last_modified))
        memset(&batchfile->last_modified, 0, sizeof(batchfile->last_modified));
    CloseHandle(h);

    for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
    {
        batchfile->cache[i].label = NULL;
        batchfile->cache[i].age = 0;
    }
    return batchfile;
}

static struct batch_context *push_batch_context(WCHAR *command, struct batch_file *batch_file, ULONGLONG pos)
{
    struct batch_context *prev = context;

    context = xalloc(sizeof(struct batch_context));
    context->file_position.QuadPart = pos;
    context->command = command;
    memset(context->shift_count, 0x00, sizeof(context->shift_count));
    context->prev_context = prev;
    context->batch_file = batch_file;
    if (batch_file) batch_file->ref_count++;

    return context;
}

static struct batch_context *pop_batch_context(struct batch_context *ctx)
{
    struct batch_context *prev = ctx->prev_context;
    struct batch_file *batchfile = ctx->batch_file;
    if (batchfile && --batchfile->ref_count == 0)
    {
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
            free((void *)batchfile->cache[i].label);
        free(batchfile->path_name);
        free(batchfile);
        ctx->batch_file = NULL;
    }
    free(ctx);
    return prev;
}

/****************************************************************************
 * WCMD_call_batch
 *
 * Open and execute a batch file.
 * On entry *command includes the complete command line beginning with the name
 * of the batch file (if a CALL command was entered the CALL has been removed).
 * *file is the name of the file, which might not exist and may not have the
 * .BAT suffix on.
 *
 * We need to handle recursion correctly, since one batch program might call another.
 * So parameters for this batch file are held in a BATCH_CONTEXT structure.
 */
RETURN_CODE WCMD_call_batch(const WCHAR *file, WCHAR *command)
{
    RETURN_CODE return_code;

    context = push_batch_context(command, find_or_alloc_batch_file(file), 0);
    return_code = WCMD_batch_main_loop();
    context = pop_batch_context(context);

    return return_code;
}

/*******************************************************************
 * WCMD_parameter_with_delims
 *
 * Extracts a delimited parameter from an input string, providing
 * the delimiters characters to use
 *
 * PARAMS
 *  s     [I] input string, non NULL
 *  n     [I] # of the parameter to return, counted from 0
 *  start [O] Optional. Pointer to the first char of param n in s
 *  raw   [I] TRUE to return the parameter in raw format (quotes maintained)
 *            FALSE to return the parameter with quotes stripped (including internal ones)
 *  wholecmdline [I] TRUE to indicate this routine is being used to parse the
 *                   command line, and special logic for arg0->1 transition
 *                   needs to be applied.
 *  delims[I] The delimiter characters to use
 *
 * RETURNS
 *  Success: The nth delimited parameter found in s
 *           if start != NULL, *start points to the start of the param (quotes maintained)
 *  Failure: An empty string if the param is not found.
 *           *start == NULL
 *
 * NOTES
 *  Return value is stored in static storage (i.e. overwritten after each call).
 *  By default, the parameter is returned with quotes removed, ready for use with
 *  other API calls, e.g. c:\"a b"\c is returned as c:\a b\c. However, some commands
 *  need to preserve the exact syntax (echo, for, etc) hence the raw option.
 */
WCHAR *WCMD_parameter_with_delims (WCHAR *s, int n, WCHAR **start,
                                   BOOL raw, BOOL wholecmdline, const WCHAR *delims)
{
    int curParamNb = 0;
    static WCHAR param[MAXSTRING];
    WCHAR *p = s, *begin;

    if (start != NULL) *start = NULL;
    param[0] = '\0';

    while (TRUE) {

        /* Absorb repeated word delimiters until we get to the next token (or the end!) */
        while (*p && (wcschr(delims, *p) != NULL))
            p++;
        if (*p == '\0') return param;

        /* If we have reached the token number we want, remember the beginning of it */
        if (start != NULL && curParamNb == n) *start = p;

        /* Return the whole word up to the next delimiter, handling quotes in the middle
           of it, e.g. a"\b c\"d is a single parameter.                                  */
        begin = p;

        /* Loop character by character, but just need to special case quotes */
        while (*p) {
            /* Once we have found a delimiter, break */
            if (wcschr(delims, *p) != NULL) break;

            /* Very odd special case - Seems as if a ( acts as a delimiter which is
               not swallowed but is effective only when it comes between the program
               name and the parameters. Need to avoid this triggering when used
               to walk parameters generally.                                         */
            if (wholecmdline && curParamNb == 0 && *p=='(') break;

            /* If we find a quote, copy until we get the end quote */
            if (*p == '"') {
                p++;
                while (*p && *p != '"') p++;
            }

            /* Now skip the character / quote */
            if (*p) p++;
        }

        if (curParamNb == n) {
            /* Return the parameter in static storage either as-is (raw) or
               suitable for use with other win32 api calls (quotes stripped) */
            if (raw) {
                memcpy(param, begin, (p - begin) * sizeof(WCHAR));
                param[p-begin] = '\0';
            } else {
                int i=0;
                while (begin < p) {
                  if (*begin != '"') param[i++] = *begin;
                  begin++;
                }
                param[i] = '\0';
            }
            return param;
        }
        curParamNb++;
    }
}

/*******************************************************************
 * WCMD_parameter
 *
 * Extracts a delimited parameter from an input string, using a
 * default set of delimiter characters. For parameters, see the main
 * function above.
 */
WCHAR *WCMD_parameter (WCHAR *s, int n, WCHAR **start, BOOL raw,
                       BOOL wholecmdline)
{
  return WCMD_parameter_with_delims (s, n, start, raw, wholecmdline, L" \t,=;");
}

/****************************************************************************
 * WCMD_fgets_helper
 *
 * Gets one line from a file/console and puts it into buffer buf
 * Pre:  buf has size noChars
 *       1 <= noChars <= MAXSTRING
 * Post: buf is filled with at most noChars-1 characters, and gets nul-terminated
         buf does not include EOL terminator
 * Returns:
 *       buf on success
 *       NULL on error or EOF
 */

static WCHAR *WCMD_fgets_helper(WCHAR *buf, DWORD noChars, HANDLE h, UINT code_page)
{
  DWORD charsRead;
  BOOL status;
  DWORD i;

  /* 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 (WCMD_read_console(h, buf, noChars, &charsRead) && charsRead) {
      /* Find first EOL */
      for (i = 0; i < charsRead; i++) {
          if (buf[i] == '\n' || buf[i] == '\r')
              break;
      }
  }
  else {
      LARGE_INTEGER filepos;
      char *bufA;
      const char *p;

      bufA = xalloc(noChars);

      /* Save current file position */
      filepos.QuadPart = 0;
      SetFilePointerEx(h, filepos, &filepos, FILE_CURRENT);

      status = ReadFile(h, bufA, noChars, &charsRead, NULL);
      if (!status || charsRead == 0) {
          free(bufA);
          return NULL;
      }

      /* Find first EOL */
      for (p = bufA; p < (bufA + charsRead); p = CharNextExA(code_page, p, 0)) {
          if (*p == '\n' || *p == '\r')
              break;
      }

      /* Sets file pointer to the start of the next line, if any */
      filepos.QuadPart += p - bufA + 1 + (*p == '\r' ? 1 : 0);
      SetFilePointerEx(h, filepos, NULL, FILE_BEGIN);

      i = MultiByteToWideChar(code_page, 0, bufA, p - bufA, buf, noChars);
      free(bufA);
  }

  /* Truncate at EOL (or end of buffer) */
  if (i == noChars)
    i--;

  buf[i] = '\0';

  return buf;
}

static UINT get_current_code_page(void)
{
    UINT code_page = GetConsoleOutputCP();
    return code_page ? code_page : GetOEMCP();
}

WCHAR *WCMD_fgets(WCHAR *buf, DWORD noChars, HANDLE h)
{
    return WCMD_fgets_helper(buf, noChars, h, get_current_code_page());
}

/****************************************************************************
 * WCMD_HandleTildeModifiers
 *
 * Handle the ~ modifiers when expanding %0-9 or (%a-z/A-Z in for command)
 *    %~xxxxxV  (V=0-9 or A-Z, a-z)
 * Where xxxx is any combination of:
 *    ~ - Removes quotes
 *    f - Fully qualified path (assumes current dir if not drive\dir)
 *    d - drive letter
 *    p - path
 *    n - filename
 *    x - file extension
 *    s - path with shortnames
 *    a - attributes
 *    t - date/time
 *    z - size
 *    $ENVVAR: - Searches ENVVAR for (contents of V) and expands to fully
 *                   qualified path
 *
 *  To work out the length of the modifier:
 *
 *  Note: In the case of %0-9 knowing the end of the modifier is easy,
 *    but in a for loop, the for end WCHARacter may also be a modifier
 *    eg. for %a in (c:\a.a) do echo XXX
 *             where XXX = %~a    (just ~)
 *                         %~aa   (~ and attributes)
 *                         %~aaxa (~, attributes and extension)
 *                   BUT   %~aax  (~ and attributes followed by 'x')
 *
 *  Hence search forwards until find an invalid modifier, and then
 *  backwards until find for variable or 0-9
 */
void WCMD_HandleTildeModifiers(WCHAR **start, BOOL atExecute)
{
  static const WCHAR *validmodifiers = L"~fdpnxsatz$";

  WIN32_FILE_ATTRIBUTE_DATA fileInfo;
  WCHAR  outputparam[MAXSTRING];
  WCHAR  finaloutput[MAXSTRING];
  WCHAR  fullfilename[MAX_PATH];
  WCHAR  thisoutput[MAX_PATH];
  WCHAR  *filepart       = NULL;
  WCHAR  *pos            = *start+1;
  WCHAR  *firstModifier  = pos;
  WCHAR  *lastModifier   = pos++;
  int   modifierLen     = 0;
  BOOL  exists          = TRUE;
  BOOL  skipFileParsing = FALSE;
  BOOL  doneModifier    = FALSE;

  /* Search forwards until find invalid character modifier */
  for (; *lastModifier && wcschr(validmodifiers, towlower(*lastModifier)); lastModifier = pos++) {
    /* Special case '$' to skip until : found */
    if (*lastModifier == L'$') {
      if (!(pos = wcschr(pos, L':'))) return; /* Invalid syntax */
      pos++;
    }
  }

  while (lastModifier > firstModifier) {
    WINE_TRACE("Looking backwards for parameter id: %s\n",
               wine_dbgstr_w(lastModifier));

    if (!atExecute && context && (*lastModifier >= '0' && *lastModifier <= '9')) {
      /* Its a valid parameter identifier - OK */
      break;

    } else {
      /* Its a valid parameter identifier - OK */
      if (for_var_is_valid(*lastModifier) && forloopcontext->variable[*lastModifier] != NULL) break;

      /* Its not a valid parameter identifier - step backwards */
      lastModifier--;
    }
  }
  if (lastModifier == firstModifier) return; /* Invalid syntax */
  /* put all modifiers in lowercase */
  for (pos = firstModifier; pos < lastModifier && *pos != L'$'; pos++)
      *pos = towlower(*pos);

  /* So now, firstModifier points to beginning of modifiers, lastModifier
     points to the variable just after the modifiers. Process modifiers
     in a specific order, remembering there could be duplicates           */
  modifierLen = lastModifier - firstModifier;
  finaloutput[0] = 0x00;

  /* Extract the parameter to play with
     Special case param 0 - With %~0 you get the batch label which was called
     whereas if you start applying other modifiers to it, you get the filename
     the batch label is in                                                     */
  if (*lastModifier == '0' && modifierLen > 1 && context->batch_file) {
    lstrcpyW(outputparam, context->batch_file->path_name);
  } else if ((*lastModifier >= '0' && *lastModifier <= '9')) {
    lstrcpyW(outputparam,
            WCMD_parameter (context -> command,
                            *lastModifier-'0' + context -> shift_count[*lastModifier-'0'],
                            NULL, FALSE, TRUE));
  } else {
    if (for_var_is_valid(*lastModifier))
        lstrcpyW(outputparam, forloopcontext->variable[*lastModifier]);
  }

  /* 1. Handle '~' : Strip surrounding quotes */
  if (outputparam[0]=='"' &&
      wmemchr(firstModifier, '~', modifierLen) != NULL) {
    int len = lstrlenW(outputparam);
    if (outputparam[len-1] == '"') {
        outputparam[len-1]=0x00;
        len = len - 1;
    }
    memmove(outputparam, &outputparam[1], (len * sizeof(WCHAR))-1);
  }

  /* 2. Handle the special case of a $ */
  if (wmemchr(firstModifier, '$', modifierLen) != NULL) {
    /* Special Case: Search envar specified in $[envvar] for outputparam
       Note both $ and : are guaranteed otherwise check above would fail */
    WCHAR *begin = wcschr(firstModifier, '$') + 1;
    WCHAR *end   = wcschr(firstModifier, ':');
    WCHAR env[MAX_PATH];
    DWORD size;

    /* Extract the env var */
    memcpy(env, begin, (end-begin) * sizeof(WCHAR));
    env[(end-begin)] = 0x00;

    size = GetEnvironmentVariableW(env, NULL, 0);
    if (size > 0) {
      WCHAR *fullpath = malloc(size * sizeof(WCHAR));
      if (!fullpath || (GetEnvironmentVariableW(env, fullpath, size) == 0) ||
          (SearchPathW(fullpath, outputparam, NULL, MAX_PATH, outputparam, NULL) == 0))
          size = 0;
      free(fullpath);
    }

    if (!size) {
      /* If env var not found, return empty string */
      finaloutput[0] = 0x00;
      outputparam[0] = 0x00;
      skipFileParsing = TRUE;
    }
  }

  /* After this, we need full information on the file,
    which is valid not to exist.  */
  if (!skipFileParsing) {
    if (!WCMD_get_fullpath(outputparam, MAX_PATH, fullfilename, &filepart)) {
      exists = FALSE;
      fullfilename[0] = 0x00;
    } else {
      exists = GetFileAttributesExW(fullfilename, GetFileExInfoStandard,
                                    &fileInfo);
    }

    /* 2. Handle 'a' : Output attributes (File doesn't have to exist) */
    if (wmemchr(firstModifier, 'a', modifierLen) != NULL) {

      doneModifier = TRUE;

      if (exists) {
        lstrcpyW(thisoutput, L"---------");
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
          thisoutput[0]='d';
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_READONLY)
          thisoutput[1]='r';
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_ARCHIVE)
          thisoutput[2]='a';
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_HIDDEN)
          thisoutput[3]='h';
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_SYSTEM)
          thisoutput[4]='s';
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_COMPRESSED)
          thisoutput[5]='c';
        /* FIXME: What are 6 and 7? */
        if (fileInfo.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
          thisoutput[8]='l';
        lstrcatW(finaloutput, thisoutput);
      }
    }

    /* 3. Handle 't' : Date+time (File doesn't have to exist) */
    if (wmemchr(firstModifier, 't', modifierLen) != NULL) {

      SYSTEMTIME systime;
      int datelen;

      doneModifier = TRUE;

      if (exists) {
        if (finaloutput[0] != 0x00) lstrcatW(finaloutput, L" ");

        /* Format the time */
        FileTimeToSystemTime(&fileInfo.ftLastWriteTime, &systime);
        GetDateFormatW(LOCALE_USER_DEFAULT, DATE_SHORTDATE, &systime,
                          NULL, thisoutput, MAX_PATH);
        lstrcatW(thisoutput, L" ");
        datelen = lstrlenW(thisoutput);
        GetTimeFormatW(LOCALE_USER_DEFAULT, TIME_NOSECONDS, &systime,
                          NULL, (thisoutput+datelen), MAX_PATH-datelen);
        lstrcatW(finaloutput, thisoutput);
      }
    }

    /* 4. Handle 'z' : File length (File doesn't have to exist) */
    if (wmemchr(firstModifier, 'z', modifierLen) != NULL) {
      /* FIXME: Output full 64 bit size (sprintf does not support I64 here) */
      ULONG/*64*/ fullsize = /*(fileInfo.nFileSizeHigh << 32) +*/
                                  fileInfo.nFileSizeLow;

      doneModifier = TRUE;
      if (exists) {
        if (finaloutput[0] != 0x00) lstrcatW(finaloutput, L" ");
        wsprintfW(thisoutput, L"%u", fullsize);
        lstrcatW(finaloutput, thisoutput);
      }
    }

    /* 4. Handle 's' : Use short paths (File doesn't have to exist) */
    if (wmemchr(firstModifier, 's', modifierLen) != NULL) {
      if (finaloutput[0] != 0x00) lstrcatW(finaloutput, L" ");

      /* Convert fullfilename's path to a short path - Save filename away as
         only path is valid, name may not exist which causes GetShortPathName
         to fail if it is provided                                            */
      if (filepart) {
        lstrcpyW(thisoutput, filepart);
        *filepart = 0x00;
        GetShortPathNameW(fullfilename, fullfilename, ARRAY_SIZE(fullfilename));
        lstrcatW(fullfilename, thisoutput);
      }
    }

    /* 5. Handle 'f' : Fully qualified path (File doesn't have to exist) */
    /*      Note this overrides d,p,n,x                                 */
    if (wmemchr(firstModifier, 'f', modifierLen) != NULL) {
      doneModifier = TRUE;
      if (finaloutput[0] != 0x00) lstrcatW(finaloutput, L" ");
      lstrcatW(finaloutput, fullfilename);
    } else {

      WCHAR drive[10];
      WCHAR dir[MAX_PATH];
      WCHAR fname[MAX_PATH];
      WCHAR ext[MAX_PATH];
      BOOL doneFileModifier = FALSE;
      BOOL addSpace = (finaloutput[0] != 0x00);

      /* Split into components */
      _wsplitpath(fullfilename, drive, dir, fname, ext);

      /* 5. Handle 'd' : Drive Letter */
      if (wmemchr(firstModifier, 'd', modifierLen) != NULL) {
        if (addSpace) {
          lstrcatW(finaloutput, L" ");
          addSpace = FALSE;
        }

        lstrcatW(finaloutput, drive);
        doneModifier = TRUE;
        doneFileModifier = TRUE;
      }

      /* 6. Handle 'p' : Path */
      if (wmemchr(firstModifier, 'p', modifierLen) != NULL) {
        if (addSpace) {
          lstrcatW(finaloutput, L" ");
          addSpace = FALSE;
        }

        lstrcatW(finaloutput, dir);
        doneModifier = TRUE;
        doneFileModifier = TRUE;
      }

      /* 7. Handle 'n' : Name */
      if (wmemchr(firstModifier, 'n', modifierLen) != NULL) {
        if (addSpace) {
          lstrcatW(finaloutput, L" ");
          addSpace = FALSE;
        }

        lstrcatW(finaloutput, fname);
        doneModifier = TRUE;
        doneFileModifier = TRUE;
      }

      /* 8. Handle 'x' : Ext */
      if (wmemchr(firstModifier, 'x', modifierLen) != NULL) {
        if (addSpace) {
          lstrcatW(finaloutput, L" ");
          addSpace = FALSE;
        }

        lstrcatW(finaloutput, ext);
        doneModifier = TRUE;
        doneFileModifier = TRUE;
      }

      /* If 's' but no other parameter, dump the whole thing */
      if (!doneFileModifier &&
          wmemchr(firstModifier, 's', modifierLen) != NULL) {
        doneModifier = TRUE;
        if (finaloutput[0] != 0x00) lstrcatW(finaloutput, L" ");
        lstrcatW(finaloutput, fullfilename);
      }
    }
  }

  /* If No other modifier processed,  just add in parameter */
  if (!doneModifier) lstrcpyW(finaloutput, outputparam);

  /* Finish by inserting the replacement into the string */
  WCMD_strsubstW(*start, lastModifier+1, finaloutput, -1);
}

extern void WCMD_expand(const WCHAR *, WCHAR *);

/*******************************************************************
 * WCMD_call - processes a batch call statement
 *
 *	If there is a leading ':', calls within this batch program
 *	otherwise launches another program.
 */
RETURN_CODE WCMD_call(WCHAR *command)
{
    RETURN_CODE return_code;
    WCHAR buffer[MAXSTRING];
    WCMD_expand(command, buffer);

    /* Run other program if no leading ':' */
    if (*command != ':')
    {
        if (*WCMD_skip_leading_spaces(buffer) == L'\0')
            /* FIXME it's incomplete as (call) should return 1, and (call ) should return 0...
             * but we need to get the untouched string in command
             */
            return_code = errorlevel = NO_ERROR;
        else
        {
            WCMD_call_command(buffer);
            /* If the thing we try to run does not exist, call returns 1 */
            if (errorlevel == RETURN_CODE_CANT_LAUNCH)
                errorlevel = ERROR_INVALID_FUNCTION;
            return_code = errorlevel;
        }
    }
    else if (context)
    {
        WCHAR gotoLabel[MAX_PATH];

        lstrcpyW(gotoLabel, param1);

        /* Save the for variable context, then start with an empty context
           as for loop variables do not survive a call                    */
        WCMD_save_for_loop_context(TRUE);

        context = push_batch_context(buffer, context->batch_file, context->file_position.QuadPart);

        /* FIXME as commands here can temper with param1 global variable (ugly) */
        lstrcpyW(param1, gotoLabel);
        WCMD_goto();

        WCMD_batch_main_loop();

        context = pop_batch_context(context);
        return_code = errorlevel;

        /* Restore the for loop context */
        WCMD_restore_for_loop_context();
  } else {
      WCMD_output_asis_stderr(WCMD_LoadMessage(WCMD_CALLINSCRIPT));
      return_code = ERROR_INVALID_FUNCTION;
  }
  return return_code;
}

void WCMD_set_label_end(WCHAR *string)
{
    static const WCHAR labelEndsW[] = L"><|& :\t";
    WCHAR *p;

    /* Label ends at whitespace or redirection characters */
    if ((p = wcspbrk(string, labelEndsW))) *p = L'\0';
}

static BOOL find_next_label(HANDLE h, ULONGLONG end, WCHAR candidate[MAXSTRING], UINT code_page)
{
    while (WCMD_fgets_helper(candidate, MAXSTRING, h, code_page))
    {
        WCHAR *str = candidate;

        /* Ignore leading whitespace or no-echo character */
        while (*str == L'@' || iswspace(*str)) str++;

        /* If the first real character is a : then this is a label */
        if (*str == L':')
        {
            /* Skip spaces between : and label */
            for (str++; iswspace(*str); str++) {}
            memmove(candidate, str, (wcslen(str) + 1) * sizeof(WCHAR));
            WCMD_set_label_end(candidate);

            return TRUE;
        }
        if (end)
        {
            LARGE_INTEGER li = {.QuadPart = 0}, curli;
            if (!SetFilePointerEx(h, li, &curli, FILE_CURRENT)) return FALSE;
            if (curli.QuadPart > end) break;
        }
    }
    return FALSE;
}

static LARGE_INTEGER li_not_found = {.QuadPart = 0x7fffffffffffffffll};

static void insert_label_cache_entry(const WCHAR *label, LARGE_INTEGER from, LARGE_INTEGER at)
{
    struct batch_file *batchfile = context->batch_file;
    unsigned int i, worst_index = ~0u, worst_age = 0;

    for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
        if (batchfile->cache[i].label)
            batchfile->cache[i].age++;
        else
            worst_index = i;
    for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
    {
        if (batchfile->cache[i].label && !lstrcmpiW(batchfile->cache[i].label, label) &&
            batchfile->cache[i].position.QuadPart == at.QuadPart)
        {
            batchfile->cache[i].age = 0;
            /* decrease 'from' position if we have a larger match */
            if (batchfile->cache[i].from.QuadPart > from.QuadPart)
                batchfile->cache[i].from.QuadPart = from.QuadPart;
            return;
        }
    }
    if (worst_index == ~0u) /* all cache lines are used, find lru */
    {
        for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
        {
            if (batchfile->cache[i].age > worst_age)
            {
                worst_index = i;
                worst_age = batchfile->cache[i].age;
            }
        }
    }
    free((void*)batchfile->cache[worst_index].label);
    batchfile->cache[worst_index].label = xstrdupW(label);
    batchfile->cache[worst_index].from = from;
    batchfile->cache[worst_index].position = at;
    batchfile->cache[worst_index].age = 0;
}

static BOOL find_label_cache_entry(const WCHAR *label, LARGE_INTEGER from, LARGE_INTEGER *at)
{
    struct batch_file *batchfile = context->batch_file;
    unsigned int i;

    for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
        batchfile->cache[i].age++;
    for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
    {
        if (batchfile->cache[i].label && !lstrcmpiW(batchfile->cache[i].label, label) &&
            batchfile->cache[i].from.QuadPart <= from.QuadPart &&
            from.QuadPart <= batchfile->cache[i].position.QuadPart)
        {
            *at = batchfile->cache[i].position;
            batchfile->cache[i].age = 0;
            return TRUE;
        }
    }
    return FALSE;
}

static void check_if_valid_label_cache(HANDLE h)
{
    struct batch_file *batchfile = context->batch_file;
    FILETIME last;
    unsigned int i;

    if (!GetFileTime(h, NULL, NULL, &last) ||
        batchfile->last_modified.dwHighDateTime != last.dwHighDateTime ||
        batchfile->last_modified.dwLowDateTime  != last.dwLowDateTime)
    {
        TRACE("Invalidating cache\n");
        batchfile->last_modified = last;
        for (i = 0; i < ARRAY_SIZE(batchfile->cache); i++)
        {
            free((void *)batchfile->cache[i].label);
            batchfile->cache[i].label = NULL;
        }
    }
}

BOOL WCMD_find_label(HANDLE h, const WCHAR *label, LARGE_INTEGER *pos)
{
    LARGE_INTEGER where = *pos, zeroli = {.QuadPart = 0};
    WCHAR candidate[MAXSTRING];
    UINT code_page = get_current_code_page();

    if (!*label) return FALSE;

    check_if_valid_label_cache(h);

    if (!SetFilePointerEx(h, *pos, NULL, FILE_BEGIN)) return FALSE;
    if (find_label_cache_entry(label, *pos, pos))
    {
        if (pos->QuadPart != li_not_found.QuadPart) return TRUE;
    }
    else
    {
        while (find_next_label(h, ~(ULONGLONG)0, candidate, code_page))
        {
            TRACE("comparing found label %s\n", wine_dbgstr_w(candidate));
            if (!lstrcmpiW(candidate, label))
            {
                BOOL ret = SetFilePointerEx(h, zeroli, pos, FILE_CURRENT);
                if (ret)
                    insert_label_cache_entry(label, where, *pos);
                return ret;
            }
        }
        insert_label_cache_entry(label, where, li_not_found);
    }
    TRACE("Label not found, trying from beginning of file\n");
    if (!SetFilePointerEx(h, zeroli, NULL, FILE_BEGIN)) return FALSE;
    if (find_label_cache_entry(label, zeroli, pos))
    {
        if (pos->QuadPart != li_not_found.QuadPart) return TRUE;
    }
    else
    {
        while (find_next_label(h, where.QuadPart, candidate, code_page))
        {
            TRACE("comparing found label %s\n", wine_dbgstr_w(candidate));
            if (!lstrcmpiW(candidate, label))
            {
                BOOL ret = SetFilePointerEx(h, zeroli, pos, FILE_CURRENT);
                if (ret)
                    insert_label_cache_entry(label, zeroli, *pos);
                return ret;
            }
        }
        insert_label_cache_entry(label, where, li_not_found);
    }
    TRACE("Reached wrap point, label not found\n");
    return FALSE;
}