feat: make bufflength a maximum width for str/bytes writes#43
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Previously bufflength acted as a minimum field width for str/bytes writes: the whole value was always written and shorter values were NUL-padded up to bufflength. This changes it to a maximum that truncates and never pads. For str the cap counts characters (applied before UTF-8 encoding, so multibyte characters are never split); for bytes it counts bytes. A value shorter than the cap is written as-is, and bufflength=None still writes the whole value. Update prepare_write accordingly and refresh the affected docstrings, guide pages, API reference and tests.
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Summary
Changes the meaning of
bufflengthforstr/byteswrites from a minimum field width to a maximum width that truncates.Previously the whole value was always written and shorter values were NUL-padded up to
bufflength(to clear a fixed-size field). Nowbufflengthis a hard cap that only ever shortens the value — it never pads.Behavior
str— the cap counts characters, applied before UTF-8 encoding, so multibyte characters are never split mid-sequence.bytes— the cap counts bytes.bufflength=Nonestill writes the whole value.write(a, str, 3, "ola")"ola"write(a, str, 3, "olá")"olá"write(a, str, 2, "ola")"ol"write(a, str, 2, "olá")"ol"write(a, str, 2, "óólá")"óó"write(a, bytes, 2, b"abc")b"ab"Changes
util/convert.py:prepare_writetruncates instead of padding.process/abstract.py,macos/process.py), guide pages (docs/guide/read-write.md), and API reference (docs/api/openprocess.md).tests/test_write_str_bytes_width.pyto assert the truncation semantics.Notes
The public method still returns the original
valuepassed in (not the truncated form), matching the existingwrite_process_memorycontract.