问题
I have file that has hex content: db90 3031 46, which should be displayed in vim as "ې" followed by "01F", but what I noticed is that it is never displayed correctly. Then I noticed It is the same in other places like in terminal and browser I always get ې01F? Why is that? Just paste that in google and try yourself you will never be able to put "ې" and 0 as next character.
回答1:
That's an Arabic character with right-to-left indicator, so you probably need to switch back to left-to-right mode, such as with U+200e.
The Unicode bidirectional stuff is rather complex - the behaviour you are seeing is probably caused by the fact that the Latin digits are marked EN = European number (a weak type), while letters such as F are marked L = left to right (a strong type).
Weak types are treated differently in the Unicode specification, such as with this quote which covers your particular case (my emphasis):
Problematic cases may occur when a right-to-left paragraph begins with left-to-right characters, or there are nested segments of different-direction text, or there are weak characters on directional boundaries. In these cases, embeddings or directional marks may be required to get the right display.
So your code point followed by a digit renders as "ې7" (I typed that 7 in after the Arabic character despite the fact it's showing up before it), while following it with a letter gives "ېX".
For what it's worth, the text "ې7" was generated here by inserting ‎ between the two characters, the HTML equivalent of the U+200e Unicode code point.
If you head on over to this UTF-8 codec site and enter %u06D0%u200e7 into the decoding section, you'll see that it comes out in your desired order (removing the %200e shows it in the order you're describing in your question).
来源：https://stackoverflow.com/questions/62294678/vim-utf-8-%db%90-character-breaks-displayed-string