Tcl 8.0 added support for binary strings. Previous versions of Tcl used null-terminated strings internally, which foils the manipulation of some types of data. Tcl now uses counted strings, so it can tolerate a null byte in a string value without truncating it.
This section describes the binary command that provides conversions between strings and packed binary data representations. The binary format command takes values and packs them according to a template. For example, this can be used to format a floating point vector in memory suitable for passing to Fortran. The resulting binary value is returned:
binary format template value ?value ...?
The binary scan command extracts values from a binary string according to a similar ...