BTRACE(8)                                               BTRACE(8)

     NAME
          btrace - trace bitblt protocol

     SYNOPSIS
          btrace [ -d [ d ]] [ -o ofile ] [ -b bfile ]

     DESCRIPTION
          Btrace eavesdrops on messages to and from /dev/bitblt,
          interprets them as messages in the bit device protocol (see
          bit(3)), and prints a readable version of the messages on a
          trace file, btrace.out by default.  After btrace is started,
          it runs in the background, tracing all subsequent graphics
          programs run in that window.  Options for btrace are:

          -o ofile  Print trace output in ofile instead of btrace.out.

          -b bfile  Dump each bitmap read or written to bfile, using
                    the format of bitmap(6). Each succeeding bitmap
                    overwrites the previous contents of file. Tweak(1)
                    or showimage(7) can be used to examine the file.

          -d        Increase the level of trace detail.  The maximum
                    level is -dd.

     FILES
          /dev/bitblt

     SOURCE
          /sys/src/cmd/btrace.c

     SEE ALSO
          bit(3), bitmap(6), graphics(2), tweak(1), showimage(7)