DL_ITERATE_PHDR(3) | Library Functions Manual | DL_ITERATE_PHDR(3)

# NAME

`dl_iterate_phdr` —
iterate over program headers

# SYNOPSIS

`#include <link.h>`

int
`dl_iterate_phdr`(int (*callback)(struct dl_phdr_info *, size_t, void*), void *data);

# DESCRIPTION

The `dl_iterate_phdr`() function iterates over all shared objects loaded into a process's address space, calling callback for each shared object, passing it information about the object's program headers and the data argument. The information about the program headers is passed in a structure that is defined as:

    struct dl_phdr_info {
    	Elf_Addr	dlpi_addr;
    	const char	*dlpi_name;
    	const Elf_Phdr	*dlpi_phdr;
    	Elf_Half	dlpi_phnum;
            unsigned long long int dlpi_adds;
            unsigned long long int dlpi_subs;
            size_t dlpi_tls_modid;
            void *dlpi_tls_data;
    };

The members of `struct dl_phdr_info` have the following meaning:

dlpi_addr
  The base address at which the shared object is mapped into the address space of the calling process.
dlpi_name
  The name of the shared object.
dlpi_phdr
  A pointer to the shared object's program headers.
dlpi_phnum
  The number of program headers in the shared object.
dlpi_adds
  The number of objects added into the main program.
dlpi_subs
  The number of objects removed from the main program.

To make it possible for programs to check whether any new members have been added, the size of the structure is passed as an argument to callback.

# SEE ALSO

ld(1), ld.elf_so(1), dlfcn(3), elf(5)

# HISTORY

The `dl_iterate_phdr` function first appeared in NetBSD 6.0.

October 16, 2010 | NetBSD 9.4