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Chunk -- Simple, fast file splitter

Chunk was written to serve one purpose, and do it well: Split files into differently-sized chunks, primarily so that large files can be transported via media that is smaller than the size of the file. In fact, the specific application for developing this particular program is copying large files onto floppy disks for transport on/off an old computer, but of course you can use it for any purpose that requires splitting a file into chunks (or combining chunks into a file).

You can download Chunk v0.1 here


The basic principle behind splitting files with chunk is to supply an input filename with extension, and Chunk produces a set of output files with a base name and increasing sequential extensions. This means, if you tell it to split with a basename of "output", it creates files called "output.000", "output.001", "output.002", etc. Unlike some splitting utilities, no additional information is written to each chunk, nor is any index file created or maintained. This is intentional, as I hate that crap (it locks you into using just that utility).

Re-combining chunks into the original file requires access to the sequentially numbered chunked files. Chunk looks for them in sequential order, and then adds them to the target filename.ext until it can't find any more. (In Diskette mode, there is no way for Chunk to know which file is the last one unless one of two conditions occur: a chunk is found that is smaller than the previous chunks, or the user presses a key to signify the last diskette has been read.)


Chunk <options> [source] [target] <options>
  [source] and [target] are either a full filename.ext or a basename (a
  filename without an extension) depending on usage (see below).
  <options> can appear anywhere on the command-line, and can be delimited
  by either "/" or "-".

Splitting options are:
  /s<num> Size of each chunk in bytes.  If size ends in K or M, size will
          be in kilobytes (1024 bytes) or megabytes (1048576 bytes).
          Example:  "chunk filename.ext basename /s256k"

  /f<num> Size of chunks appropriate for a blank/formatted floppy of size 
          Available sizes are 160, 180, 320, 360, 720, 1200, and 1440.
          Example:  "chunk filename.ext basename /f360"

  /n<num> Number of chunks to make.  File will be split into N chunks.
          Example:  "chunk filename.ext basename /n5"

  /a      Autosize mode enabled.  Size of each chunk will be determined
          by the amount of free space on the target.  Diskette mode required.
          Example:  "chunk /d /a filename.ext a:basename"

Combining options are:
  /c      Combine split parts into file.  Chunk extension must be zero-padded.
          Example: "chunk /c basename filename.ext"

Diskette options are:
  /d      Diskette mode enabled.  User will be prompted to switch disks.
          Example (splitting): "chunk /d /f360 filename.ext a:basename"
          Example (combining): "chunk /c /d a:basename filename.ext"

  /e      Erase contents of diskette before writing target.
          There is no user prompting with this command -- use with caution!
          Example:  "chunk /d /a /e filename.ext a:basename"

General options are:
  /h[w]   Print command-line usage.  If called as /hw, help text will
          be written to the file "chunk.txt"

  /v[c]   Verify readability of target file(s).  This re-reads the target
          to ensure it is readable.  If called as /vc, data buffers are
          compared byte-for-byte to ensure file was written correctly.
          Example: "chunk filename.ext basename /n5 /v"

  /o      Overwrite.  If set, target(s) will be overwritten without prompting.
          Example: "chunk filename.ext basename /n5 /o"


Splitting a file into disk-sized chunks: chunk filename.ext basename /f720
Splitting a file into four parts: chunk filename.ext basename /n4
Splitting a file onto floppy disks, using all available disk space: chunk filename.ext a:basename /d /a /e
Combining chunks into a file: chunk /c c:\import\basename c:\output\filename.ext
Combining chunks located on multiple disks into a file: chunk a:basename filename.ext /d

You get the idea.

To-Do List:

Known Bugs/Issues:

License and source code:

This program is free for use by any individual for any purpose, under the understanding that the author of this program is not liable for any damages incurred from the use or mis-use of this program. I wrote it and I use it myself, but that doesn't mean you have to, and I cannot be held responsible if something bad happens.

The source code is included in the source\ directory. You should be able to recompile and re-make the executable using everything there, although some editing of the build.bat file will be necessary for your system. Turbo Pascal 7.0 is required, although you should be able to use anything that properly implements the objects unit (specifically TStream and its descendants).

If you make any additions or corrections to the source code, let me know so that I can incorporate them into the official distributable file on


Greets to the owb crew, and anyone who still uses computers more than two decades old.

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This page's content was last modified on Dec 21, 2015 4:31 pm.
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