HP UX Software Transition Kit (STK) manual Return Values, Parameters

Table 24 Parameters

Parameter	Definition
file	Used to construct a pathname to the shared library file.
	If files contain a slash character (/), dlopen uses the file
	argument itself as the pathname. If not, dlopen searches
	a series of directories for file.
	• Any directories specified by the dynamic search path,
	which is set by calling dlsetlibpath
	• Any directories specified by the environment variable
	LD_LIBRARY_PATH.
	• Any directories specified by the variable SHLIB_PATH.
	• Any directories specified by the RPATH of the calling
	load module.
	• The default library search path.
	• The current working directory.

flags Mode

RTLD_LAZY

RTLD_NOW

RTLD_GLOBAL

RTLD_LOCAL

RTLD_VERBOSE

Definition

Under this mode, only references to data symbols are relocated when the library is loaded. References to functions are not relocated until a given function is invoked for the first time. This mode results in better performance, because a process may not reference all of the functions in any given shared object.

Under this mode, all necessary relocations are performed when the library is first loaded. This can cause some wasted effort if relocations are performed for functions that are never referenced. But it is useful for applications that need to know as soon as an object is loaded that all symbols referenced during execution are available.

The shared library's symbols are made available for the relocation processing of any other object. In addition, symbol lookup using dlopen(0, mode) and an associated dlsym() allows objects loaded with RTLD_GLOBAL to be searched.

The shared library's symbols are made available for relocation processing only to objects loaded in the same dlopen invocation. If neither RTLD_GLOBAL nor RTLD_LOCAL are specified, the default is

RTLD_LOCAL.

Displays verbose messages when binding symbols.

Return Values

A successful dlopen call returns to the process a handle which the process can use on subsequent calls to dlsym and dlclose. This value must not be interpreted in any way by the process.

The dlopen routine returns NULL under the following conditions:

•file cannot be found.

•file cannot be opened for reading.

The dlopen Shared Library Management Routines 149