write bytes given as hex sequences into a file at a given offset, with sfk setbytes for Windows, Mac OS X and Linux.

sfk setbytes filename offset [data] [data2] [...]
sfk ... +setbytes filename offset

write binary or text data into a target file at an offset.

data can be given as a series of byte blocks each
starting with 0x or as plain text. all data parameters
are joined into one long byte block which cannot be
larger than 100000 bytes.

   -dump  create a hexdump of the changed output.
          by default only the input is shown.
   -spat  support slash patterns like foo\tbar.
          type "sfk help pat" for details.
   -repeat=n  repeat the next data n times.

command chaining
   accepts binary chain input.

see also
   sfk hexdump    show binary file contents
   sfk partcopy   copy part of a file

web reference

   sfk setbytes out.dat 20 0xf1f2f3f4 "foo bar"
      write 4 bytes with codes f1, f2, f3, f4 into
      out.dat at offset 20 followed by the words
      "foo", a space, and "bar".
   sfk setbytes out.dat 20 -spat "foo\tbar" 0x00
      write "foo" then a TAB character then "bar"
      followed by a binary zero. note that a slash
      pattern does not support \x00 zero bytes.
   sfk echo 0xf1f2f3f4 +hextobin +setbytes out.dat 20
      write 4 bytes prepared by previous commands.
   sfk echo -pure "c:\foo.dat" +setbytes out.dat 20
      write a filename string as pure as possible,
      without pattern interpretation or (CR)LF,
      into out.dat at offset 20.
   sfk setbytes out.dat 0 -repeat=10000 a -spat "\n"
      fill the first 10000 bytes of out.dat with
      character a then add a single line feed.