elf_cntl(3ELF)						       ELF Library Functions						    elf_cntl(3ELF)

NAME

       elf_cntl - control an elf file descriptor

SYNOPSIS

       cc [ flag ... ] file ... -lelf [ library ... ]
       #include <libelf.h>

       int elf_cntl(Elf *elf, Elf_Cmd cmd);

DESCRIPTION

       elf_cntl()  instructs  the  library  to	modify	its behavior with respect to an ELF descriptor, elf.  As elf_begin(3ELF) describes, an ELF
       descriptor can have multiple activations, and multiple ELF descriptors may share a single file descriptor. Generally,  elf_cntl()  commands
       apply to all activations of elf. Moreover, if the ELF descriptor is associated with an archive file, descriptors for members within the ar-
       chive will also be affected as described below. Unless stated otherwise, operations on archive members do not affect the descriptor for the
       containing archive.

       The cmd argument tells what actions to take and may have the following values:

       ELF_C_FDDONE    This  value tells the library not to use the file descriptor associated with elf. A program should use this command when it
		       has requested all the information it cares to use and wishes to avoid the overhead of reading the rest  of  the	file.  The
		       memory  for all completed operations remains valid, but later file operations, such as the initial elf_getdata() for a sec-
		       tion, will fail if the data are not in memory already.

       ELF_C_FDREAD    This command is similar to ELF_C_FDDONE, except it forces the library to read the rest of the file. A  program  should  use
		       this  command  when  it	must  close  the  file	descriptor  but  has not yet read everything it needs from the file. After
		       elf_cntl() completes the ELF_C_FDREAD command, future operations, such as elf_getdata(), will use the memory version of the
		       file without needing to use the file descriptor.

       If elf_cntl() succeeds, it returns 0. Otherwise elf was NULL or an error occurred, and the function returns -1.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Stable			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       elf(3ELF), elf_begin(3ELF), elf_getdata(3ELF), elf_rawfile(3ELF), libelf(3LIB), attributes(5)

NOTES

       If  the	program  wishes  to use the ``raw'' operations (see elf_rawdata(), which elf_getdata(3ELF) describes, and elf_rawfile(3ELF)) after
       disabling the file descriptor with ELF_C_FDDONE or ELF_C_FDREAD, it must execute the raw operations explicitly beforehand.  Otherwise,  the
       raw file operations will fail. Calling elf_rawfile() makes the entire image available, thus supporting subsequent elf_rawdata() calls.

SunOS 5.10							    11 Jul 2001 						    elf_cntl(3ELF)