unpack
Unpack data from binary string
&reftitle.description;
arrayunpack
stringformat
stringdata
Unpacks from a binary string into an array according to the given
format.
The unpacked data is stored in an associative array. To
accomplish this you have to name the different format codes and
separate them by a slash /. If a repeater argument is present,
then each of the array keys will have a sequence number behind
the given name.
&reftitle.parameters;
format
See pack for an explanation of the format codes.
data
The packed data.
&reftitle.returnvalues;
Returns an associative array containing unpacked elements of binary
string.
&reftitle.changelog;
&Version;
&Description;
5.5.0
Changes were made to bring this function into line with Perl:
The "a" code now retains trailing NULL bytes.
The "A" code now strips all trailing ASCII whitespace (spaces, tabs,
newlines, carriage returns, and NULL bytes).
The "Z" code was added for NULL-padded strings, and removes trailing
NULL bytes.
&reftitle.examples;
unpack example
]]>
The resulting array will contain the entries "chars" with value
4 and "int" with 160.
unpack example with a repeater
]]>
The resulting array will contain the entries "chars1",
"chars2" and "int".
&reftitle.notes;
Note that PHP internally stores integral values as signed. If you
unpack a large unsigned long and it is of the same size as PHP
internally stored values the result will be a negative number
even though unsigned unpacking was specified.
Be aware that if you do not name an element, an empty string is used.
If you do not name more than one element, this means
that some data is overwritten as the keys are the same such as in:
unpack example with unnamed keys
]]>
The resulting array will contain the entries "1" with value
160 and "2" with 66. The
first value from the c specifier is
overwritten by the first value from the n
specifier.
&reftitle.seealso;
pack