cpack

• Examples
• Frequently asked questions
• Things to do

cpack is a packaging utility for C source code, but can be applied to other files as well. cpack is in the same spirit as "shar" files, which are self-extracting shell archive files.

Usage: cpack [option] file ... [ > outfile.c]

Options are:

-b

Next file is binary

@file

file is a text list of files, one file per line (generated with ls -1 or dir /b or dir /col=1 depending on your OS). If the file is to be processed as binary, "-b " should appear before the file name (do not include the quotes, but do put in one space).

Note: all directory separators must be a slash (/) character regardless of the OS.

Examples

Packing

cpack 0Readme.txt Makefile mycode.c > mycode-dist.c

dir /b *.c Makefile > dirlist.txt
cpack @dirlist.txt > this-dist.c

cpack Makefile file1.c -b table.xls file2.c > spreadsheet.c

Unpacking

unpacking is the easy part.

cc this-dist.c
./this-dist

If you are using a Microsoft ^® C compiler, you may need to increase the size of the heap

cl /Zm400 this-dist.c
.\this-dist

FAQ

Q: Why not use getopt?
A: getopt is non standard on platforms besides unix. The code would be complicated by #ifdefs if getopt was implemented.

Q: The resulting file is so large!

A:

Disk space is cheap Most people have High Speed Internet If the file is compressed with zip, it can be decompressed with either unzip, or gunzip (single file in a .zip archive). If the files are small enough, a zipped cpack file will be smaller than the zipped archive of the collection of files. Previous Q: is not technically a question, and this A: is a comment, not an answer. :-)

Q: What if I don't have a C compiler?

A:

cpack is intended for archiving source code which is a variant of C. (C, C++, C#) Most source will require a C compiler, anyway. If you don't have a C compiler, you cannot use the C source. The cpack archive is still human-readable. If the source is not C code, the cpack can still be pre-compiled and distributed as a self-extracting executable. (The resulting executable is often smaller than a comparable "tar" file)

Q: Why not write this in Java?
A: Java has .jar files, and C is more portable than Java.

Things to do

These things are not done because they are so unportable.

• Allow for original date modification to be restored
• Allow for other directory separators (Micorosoft \ OpenVMS [.])
• Automatic md5 verification after extraction
• Option not to overwrite files