bzexe utility allows you to compress executables in place and have them
automatically uncompress and execute when you run them (at a penalty
in performance). For example if you execute bzexe /bin/cat it
will create the following two files:
-r-xr-xr-x 1 root bin 9644 Feb 11 11:16 /bin/cat
-r-xr-xr-x 1 bin bin 24576 Nov 23 13:21 /bin/cat~
/bin/cat~ is the original file and /bin/cat is the self-uncompressing
executable file. You can remove /bin/cat~ once you are sure that
/bin/cat works properly.
This utility is most useful on systems with very small disks.
The compressed executable is a shell script. This may create some
security holes. In particular, the compressed executable relies
on the PATH environment variable to find
gzip and some other utilities
(tail, chmod, ln, sleep).