Defined in rt_sys.h, this function writes
the contents of a buffer to a file previously opened with _sys_open().
Syntaxint _sys_write(FILEHANDLEfh, const unsigned char *buf, unsignedlen, intmode);
Note
The mode parameter is here for historical reasons. It contains nothing useful and must be ignored.
The return value is either:
a positive number representing the number of characters not written (so any nonzero return value denotes a failure of some sort)
a negative number indicating an error.
- Reference
Using ARM® C and C++ Libraries and Floating-Point Support:
PDF version