dlopen(libfile::AbstractString [, flags::Integer]; throw_error:Bool = true)
Load a shared library, returning an opaque handle.
The extension given by the constant
.dylib) can be omitted from the
libfile string, as it is automatically appended if needed. If
libfile is not an absolute path name, then the paths in the array
DL_LOAD_PATH are searched for
libfile, followed by the system load path.
The optional flags argument is a bitwise-or of zero or more of
RTLD_FIRST. These are converted to the corresponding flags of the POSIX (and/or GNU libc and/or MacOS) dlopen command, if possible, or are ignored if the specified functionality is not available on the current platform. The default flags are platform specific. On MacOS the default
dlopen flags are
RTLD_LAZY|RTLD_DEEPBIND|RTLD_GLOBAL while on other platforms the defaults are
RTLD_LAZY|RTLD_DEEPBIND|RTLD_LOCAL. An important usage of these flags is to specify non default behavior for when the dynamic library loader binds library references to exported symbols and if the bound references are put into process local or global scope. For instance
RTLD_LAZY|RTLD_DEEPBIND|RTLD_GLOBAL allows the library's symbols to be available for usage in other shared libraries, addressing situations where there are dependencies between shared libraries.
If the library cannot be found, this method throws an error, unless the keyword argument
throw_error is set to
false, in which case this method returns
dlopen_e(libfile::AbstractString [, flags::Integer])
dlopen, except returns
C_NULL instead of raising errors. This method is now deprecated in favor of
dlopen(libfile::AbstractString [, flags::Integer]; throw_error=false).
RTLD_DEEPBIND RTLD_FIRST RTLD_GLOBAL RTLD_LAZY RTLD_LOCAL RTLD_NODELETE RTLD_NOLOAD RTLD_NOW
Enum constant for
dlopen. See your platform man page for details, if applicable.
Look up a symbol from a shared library handle, return callable function pointer on success.
Look up a symbol from a shared library handle, silently return
C_NULL on lookup failure. This method is now deprecated in favor of
dlsym(handle, sym; throw_error=false).
Close shared library referenced by handle.
For the very common pattern usage pattern of
try hdl = dlopen(library_name) ... do something finally dlclose(hdl) end
We define a
dlclose() method that accepts a parameter of type
Nothing, so that user code does not have to change its behavior for the case that
library_name was not found.
File extension for dynamic libraries (e.g. dll, dylib, so) on the current platform.
Searches for the first library in
names in the paths in the
DL_LOAD_PATH, or system library paths (in that order) which can successfully be dlopen'd. On success, the return value will be one of the names (potentially prefixed by one of the paths in locations). This string can be assigned to a
global const and used as the library name in future
ccall's. On failure, it returns the empty string.
dlopen, the paths in this list will be searched first, in order, before searching the system locations for a valid library handle.