1.Dd November 29, 2010 2.Dt dyld 3 3.Sh NAME 4.Nm _dyld_image_count, 5.Nm _dyld_get_image_header, 6.Nm _dyld_get_image_vmaddr_slide, 7.Nm _dyld_get_image_name, 8.Nm _dyld_register_func_for_add_image, 9.Nm _dyld_register_func_for_remove_image, 10.Nm NSVersionOfRunTimeLibrary, 11.Nm NSVersionOfLinkTimeLibrary 12.Nm _NSGetExecutablePath 13.Sh SYNOPSIS 14.In mach-o/dyld.h 15.Ft uint32_t 16.Fo _dyld_image_count 17.Fa "void" 18.Fc 19.Ft const struct mach_header* 20.Fo _dyld_get_image_header 21.Fa "uint32_t image_index" 22.Fc 23.Ft intptr_t 24.Fo _dyld_get_image_vmaddr_slide 25.Fa "uint32_t image_index" 26.Fc 27.Ft const char* 28.Fo _dyld_get_image_name 29.Fa "uint32_t image_index" 30.Fc 31.Ft void 32.Fo _dyld_register_func_for_add_image 33.Fa "void \*[lp]*func\*[rp]\*[lp]const struct mach_header* mh, intptr_t vmaddr_slide\*[rp]" 34.Fc 35.Ft void 36.Fo _dyld_register_func_for_remove_image 37.Fa "void \*[lp]*func\*[rp]\*[lp]const struct mach_header* mh, intptr_t vmaddr_slide\*[rp]" 38.Fc 39.Ft int32_t 40.Fo NSVersionOfRunTimeLibrary 41.Fa "const char* libraryName" 42.Fc 43.Ft int32_t 44.Fo NSVersionOfLinkTimeLibrary 45.Fa "const char* libraryName" 46.Fc 47.Ft int 48.Fo _NSGetExecutablePath 49.Fa "char* buf" 50.Fa "uint32_t* bufsize" 51.Fc 52.Sh DESCRIPTION 53These routines provide additional introspection of dyld beyond that provided by 54.Fn dlopen 55and 56.Fn dladdr 57. 58.Pp 59.Fn _dyld_image_count 60returns the current number of images mapped in by dyld. Note that using this 61count to iterate all images is not thread safe, because another thread 62may be adding or removing images during the iteration. 63.Pp 64.Fn _dyld_get_image_header 65returns a pointer to the mach header of the image indexed by image_index. If 66.Fa image_index 67is out of range, NULL is returned. 68.Pp 69.Fn _dyld_get_image_vmaddr_slide 70returns the virtural memory address slide amount of the image indexed by 71.Fa image_index. 72If 73.Fa image_index 74is out of range zero is returned. 75.Pp 76.Fn _dyld_get_image_name 77returns the name of the image indexed by 78.Fa image_index. 79The C-string continues to be owned by dyld and should not deleted. 80If 81.Fa image_index 82is out of range NULL is returned. 83.Pp 84.Fn _dyld_register_func_for_add_image 85registers the specified function to be called when a new image is added 86(a bundle or a dynamic shared library) to the program. When this function is 87first registered it is called for once for each image that is currently part of 88the process. 89.Pp 90.Fn _dyld_register_func_for_remove_image 91registers the specified function to be called when an image is removed 92(a bundle or a dynamic shared library) from the process. 93.Pp 94.Fn NSVersionOfRunTimeLibrary 95returns the current_version number of the currently loaded dylib 96specifed by the libraryName. The libraryName parameter would be "bar" for /path/libbar.3.dylib and 97"Foo" for /path/Foo.framework/Versions/A/Foo. This function returns -1 if no such library is loaded. 98.Pp 99.Fn NSVersionOfLinkTimeLibrary 100returns the current_version number that the main executable was linked 101against at build time. The libraryName parameter would be "bar" for /path/libbar.3.dylib and 102"Foo" for /path/Foo.framework/Versions/A/Foo. This function returns -1 if the main executable did not link 103against the specified library. 104.Pp 105.Fn _NSGetExecutablePath 106copies the path of the main executable into the buffer 107.Fa buf . 108The 109.Fa bufsize 110parameter should initially be the size of the buffer. This function returns 0 if the path was successfully copied, 111and * 112.Fa bufsize 113is left unchanged. 114It returns -1 if the buffer is not large enough, and * 115.Fa bufsize 116is set to the size required. 117Note that 118.Fn _NSGetExecutablePath 119will return "a path" to the executable not a "real path" to the executable. 120That is, the path may be a symbolic link and not the real file. With deep directories the total bufsize 121needed could be more than MAXPATHLEN. 122.Sh SEE ALSO 123.Xr dlopen 3 124.Xr dladdr 3 125.Xr dyld 1 126http://developer.apple.com/documentation/DeveloperTools/Conceptual/MachOTopics/index.html