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Stream::find() not working for values above 0x7F #119
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Sounds like sloppy typing indeed, would be good to fix. I haven't looked closely, but I think that using
charandchar*in the public API is ok (since that's the common typing for a string), but internally, the code should make sure to either convert the target touint8_t, or convert the thing to compare with tochartoo.Did you try changing the typing to confirm that this indeeds fixes the problem?
Note that development on the non-arch-specific code happens at ArduinoCore-API repo now, so I'll transfer this issue there.
- linked a pull request that will close this issueMigrate Stream search internals from char to uint8_t #274
on Jun 8, 2026
I found out that the
Stream::find()(and all related functions, findUntil() etc), does not work when the sequence to be found contains values above 0x7F. I believe this is because the function uses char instead of uint8_t.Example, using these definitions:
a == bis false, and therefore the find() method does not return a match when supplied a uint8_t[] array containing values above 0x7F, since the array gets casted to char. Changing the declaration of find() to uint8_t should solve the issue.I don't know if ignoring values above 0x7F is the intended behaviour, but if that is the case I think the documentation should be more specific and explain this case better. In any case, if the current behaviour is the intended one, i do not see the reason behind it.
First time reporting something on Arduino, sorry if I overlooked something obvious.