问题
I have to translate some memory contents into a string, using ASCII encoding. For example:
0x6A636162
But I am not sure how to break that up, to be translated into ASCII. I think it has something to do with how many bits are in a char/digit, but I am not sure how to go about doing so (and of course, I would like to know more of the reasoning behind it, not just "how to do it").
回答1:
ASCII uses 7 bits to encode a character (http://en.wikipedia.org/wiki/ASCII). However, it's common to encode characters using 8 bits instead (note that technically this isn't ASCII). Thus, you'd need to split your data into 8-bit chunks and match that to an ASCII table.
If you're using a specific programming language, it may have a way to translate an ASCII code to a character. For instance, Ruby has the .chr method, Python has the chr() built-in function, and in C you can printf("%c", number).
Note that each nibble (4 bits) can be represented as one hexadecimal digit, so for the sample string you show, each 8-bit "chunk" would be:
0x6A
0x63
0x61
0X62
the string reads "jcab" :)
来源：https://stackoverflow.com/questions/9449872/translating-memory-contents-into-a-string-via-ascii-encoding