126 lines
2.9 KiB
C
126 lines
2.9 KiB
C
/*++
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Copyright (c) 1992, 1993 Microsoft Corporation
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Module Name:
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packstr.c
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Abstract:
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Contains functions for packing strings into buffers that also contain
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structures.
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Author:
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From LAN Manager netlib.
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Rita Wong (ritaw) 2-Mar-1993
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Environment:
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User Mode - Win32
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Revision History:
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--*/
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#include <procs.h>
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BOOL
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NwlibCopyStringToBuffer(
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IN LPCWSTR SourceString OPTIONAL,
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IN DWORD CharacterCount,
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IN LPCWSTR FixedDataEnd,
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IN OUT LPWSTR *EndOfVariableData,
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OUT LPWSTR *VariableDataPointer
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)
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/*++
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Routine Description:
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This routine puts a single variable-length string into an output buffer.
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The string is not written if it would overwrite the last fixed structure
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in the buffer.
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Arguments:
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SourceString - Supplies a pointer to the source string to copy into the
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output buffer. If SourceString is null then a pointer to a zero terminator
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is inserted into output buffer.
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CharacterCount - Supplies the length of SourceString, not including zero
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terminator. (This in units of characters - not bytes).
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FixedDataEnd - Supplies a pointer to just after the end of the last
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fixed structure in the buffer.
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EndOfVariableData - Supplies an address to a pointer to just after the
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last position in the output buffer that variable data can occupy.
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Returns a pointer to the string written in the output buffer.
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VariableDataPointer - Supplies a pointer to the place in the fixed
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portion of the output buffer where a pointer to the variable data
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should be written.
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Return Value:
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Returns TRUE if string fits into output buffer, FALSE otherwise.
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--*/
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{
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DWORD CharsNeeded = (CharacterCount + 1);
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//
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// Determine if source string will fit, allowing for a zero terminator.
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// If not, just set the pointer to NULL.
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//
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if ((*EndOfVariableData - CharsNeeded) >= FixedDataEnd) {
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//
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// It fits. Move EndOfVariableData pointer up to the location where
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// we will write the string.
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//
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*EndOfVariableData -= CharsNeeded;
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//
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// Copy the string to the buffer if it is not null.
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//
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if (CharacterCount > 0 && SourceString != NULL) {
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(VOID) wcsncpy(*EndOfVariableData, SourceString, CharacterCount);
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}
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//
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// Set the zero terminator.
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//
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*(*EndOfVariableData + CharacterCount) = L'\0';
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//
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// Set up the pointer in the fixed data portion to point to where the
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// string is written.
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//
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*VariableDataPointer = *EndOfVariableData;
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return TRUE;
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}
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else {
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//
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// It doesn't fit. Set the offset to NULL.
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//
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*VariableDataPointer = NULL;
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return FALSE;
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}
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}
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