MOJOELF_getentry

Obtain an ELF binary's official entry point.

Header File

Defined in <mojoelf.h>

Syntax

const void * MOJOELF_getentry(void *lib);

Function Parameters

Return Value

(const void *) Returns the address of the ELF binary's entry point.

Remarks

You almost certainly do not want or need this function.

This returns the address where a process should start executing (which would, in most cases, perform some initialization code that eventually calls the main function).

Not all ELF binaries have an entry point, in which case this will return NULL, but this scenario is not an error in itself. Shared libraries, the most common thing one would load, often do not have an entry point (but they may! One can run glibc's libc.so on a Linux box as if it were a program and it will print information to stdout.) Binaries meant to be run as standalone programs always have an entry point, out of necessity.

ELF binaries might have initialization code that runs at load time (DT_INIT sections, etc), which is unrelated to the entry point, and is handled during MOJOELF_dlopen_mem() or MOJOELF_dlopen_file().

If you are looking to load a shared library and call into a function in it, this is not the function you should call. Instead, obtain the function's address through a call to MOJOELF_dlsym(). This function is useful if you want to load and run an ELF program, which has other complications beyond just calling into a function pointer.

Passing in a NULL lib will return NULL.

Thread Safety

this function is not thread-safe.

Version

This function is available since MojoELF 1.0.0.

CategoryAPI, CategoryAPIFunction, CategoryMojoELF