Hello,
I have been asked for examples and use cases. Github repo has been updated.
I do also have doubts on if it's worth it. If a library like this existed I
would be definitely using it, make conversions, does take care of
alignment, can manage unaligned data and endianness. etc.
But I am not really sure if someone apart from me would find it interesting
(long time ago I haven't seen a protocol unaligned with different
endianess).
Waiting for your feedback!
/*
* Syntax for the function is as follows.
* %[p][n][a][lb][01r]{i,y,w,d,q,s}
*
* All the characters that don't follow this will be treated as raw chars
* to be written as they are.
*
* Data type
* * i - bit
* * y - byte
* * w - 2 byte word
* * d - 4 byte word
* * q - 8 byte word
* * s - string without termination (use strlen()+1 in quantity to null)
*
* Data value
* * 0 - fill the specified space with zeros
* * 1 - fill the specified space with ones
* * r - fill the specified space with random data
*
* String data type is not valid in this case. When quantity is also
* specified, use l/b to separate: %5b0 -> 5 bits of value 0
*
* Endianess. No conversion by default
* * l - little endian
* * b - big endian
*
* Alignment. No alignment by default
* * a - align this to it's datatype
* bits are aligned to byte
*
* Quantity. One by default
* * n - number of same datatype (placed together)
* this denotes length of string, padded with 0
*
* Pointer. Default everything is passed by value
* * p - specify that passed parameter is a pointer to value(s)
*
* Obviously, when quantity is specified, and datatype is not bits, p
* is required.
*
* Some examples:
* * %4lw - 4 little endian 2 byte word
* * %2i - 2 bits 'ab' from value b'000000ab'
* * %2bi - 2 bits 'ab' from value b'000000ba'
* * %2li - 2 bits 'ab' from value b'ab000000'
* * %5y
*
* Calling functions example:
* int32_t dw[]=[1,2,3,4]
*
* v = writebv("%lw%2i%ay%p4d", 2047, 3, 'n', dw);
*
* in a big endian computer
* // *v = 0xff07c06e00000001000000020000000300000004
*
* struct my_data_t {
* uint16_t a;
* uint8_t b:2;
* uint8_t unused1:6;
* uint8_t c;
* uint32_t d[4];
* } *my_data;
* char letter;
*
* // If we want to have all extracted from the blob
* my_data = readbv(v, "%lw%2i%ay%p4d");
*
* // If we just want to extract the char
* readb(v, "%0w%2l0i%ay%4l0d", &letter);
*
* // We have aligned data, but if we removed the 'a' from %ay, we
* wouldn't have unaligned data and this would still work.
*
*/
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