捕获正在写入打开文件描述符的数据

       -e write=set
                   Perform a full hexadecimal and ASCII dump of all the
                   data written to file descriptors listed in the spec-
                   ified  set.  For example,to see all output activity
                   on file descriptors 3 and 5 use -e write=3,5.   Note
                   that  this is independent from the normal tracing of
                   the write(2) system call which is controlled by  the
                   option -e trace=write.