unpack

Syntax

unpack(format, buf)

Arguments

format is a format string.

  • A format character may be preceded by an integral repeat count. For example, the format string '4h' means exactly the same as 'hhhh'.

  • Whitespace characters between formats are ignored; a count and its format must not contain whitespace though.

  • For the 's' format character, the count is interpreted as the length of the bytes, not a repeat count like for the other format characters; for example, '10s' means a single 10-byte string, while '10c' means 10 characters. If a count is not given, it defaults to 1. The string is truncated or padded with null bytes as appropriate to make it fit.

buf is a bytes object of STRING or BLOB type. The size of buf in bytes must match the size required by the format.

Details

Unpack from the buf according to the format string specified by format. The result is a tuple with the unpacked data even if it contains exactly one item.

Examples

res = pack("N",1);
res1 = unpack("N", res);
print(res1)
// output
(1)

res = pack("3s i", `123, 3)
res1 = unpack("3s i",  res);
print(res1)
// output
("123",3)

res = pack("3s i", `123, 3)
res2 = unpack("3s i",  blob(res));
print(res2)
// output
("123",3)