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Top Forums UNIX for Advanced & Expert Users What does LD_PRELOAD signify? Post 101801 by jim mcnamara on Monday 13th of March 2006 10:32:09 AM
Old 03-13-2006
LD_PRELOAD asks dld to load a named shared library first, it's called interposing a library.

In simple terms, if you have a call to some function in libc like printf, and another printf function in myshlib.sl, then by loading myshlib first, the functionality of myshlib is interposed, ie. replaces the functionality of the original libc call. It's used mainly for profiling and debugging. It's also one of the reasons why secure systems don't allow everybody access to shell. You can hijack any program with it.

I did not know that HPUX supported it.... if it does, then there's your answer.
 

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TSOCKS(1)                                                     General Commands Manual                                                    TSOCKS(1)

NAME
tsocks - Shell wrapper to simplify the use of the tsocks(8) library to transparently allow an application to use a SOCKS proxy SYNOPSIS
tsocks [application [application's arguments]] or tsocks [-on|-off] or tsocks DESCRIPTION
tsocks is a wrapper between the tsocks library and the application what you would like to run socksified. OPTIONS
[application [application's arguments]] run the application as specified with the environment (LD_PRELOAD) set such that tsocks(8) will transparently proxy SOCKS connec- tions in that program [-on|-off] this option adds or removes tsocks(8) from the LD_PRELOAD environment variable. When tsocks(8) is in this variable all executed applications are automatically socksified. If you want to use this function, you HAVE to source the shell script from yours, like this: "source /usr/bin/tsocks" or ". /usr/bin/tsocks" Example: ". tsocks -on" -- add the tsocks lib to LD_PRELOAD (don't forget the leading dot!) ". tsocks -off" -- remove the tsocks lib from LD_PRELOAD (don't forget the leading dot!) [-show|-sh] show the current value of the LD_PRELOAD variable <without any argument> create a new shell with LD_PRELOAD including tsocks(8). SEE ALSO
tsocks.conf(5) tsocks(8) AUTHOR
This script was created by Tamas SZERB <toma@rulez.org> for the debian package of tsocks. It (along with this manual page) have since been adapted into the main tsocks project and modified. TSOCKS
TSOCKS(1)
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