Linux LD_PRELOAD example


Idea
  Fake library system call using fake library with LD_PRELOAD.
  Minimal dependencies (BASH, gcc, dlfcn.h)

Flow
  # run the bash demonstrator script ./run.sh:

  [f@dhcp-lab-xyz ld_preload_example]$ ./run.sh
  Compile stuff.
  .compiled ok 00 (ecodes:00)
  Normal rand operation:
  my random number: 1038560620
  my random number: 1814138293
  my random number: 431968634
  Overriden rand operation:
  my random number: 1
  my random number: 2
  my random number: 3


Files
  run.sh                    BASH demonstrator
  get_rand.c                main C code calling rand system call
  mylibrand.c               fake library used for overriding rand call

License
  GPL v2
  http://www.gnu.org/licenses/gpl-2.0.html