elf_cntl(3) [freebsd man page]

ELF_CNTL(3)						   BSD Library Functions Manual 					       ELF_CNTL(3)

NAME

     elf_cntl -- control an elf file descriptor

LIBRARY

     ELF Access Library (libelf, -lelf)

SYNOPSIS

     #include <libelf.h>

     int
     elf_cntl(Elf *elf, Elf_Cmd cmd);

DESCRIPTION

     Function elf_cntl() controls the ELF library's subsequent use of the file descriptor used to create ELF descriptor elf.

     Argument cmd informs the library of the action to be taken:

     ELF_C_FDDONE  This value instructs the ELF library not to perform any further I/O on the file descriptor associated with argument elf.  For
		   ELF descriptors opened with mode ELF_C_WRITE or ELF_C_RDWR subsequent elf_update() operations on the descriptor will fail.

     ELF_C_FDREAD  This value instructs the ELF library to read in all necessary data associated with ELF descriptor elf into memory so that the
		   underlying file descriptor can be safely closed with command ELF_C_FDDONE.

     Argument elf must be an ELF descriptor associated with a file system object (e.g., an ar(1) archive, an ELF file, or other data file).

IMPLEMENTATION NOTES

     Due to use of mmap(2) internally, this function is a no-op for ELF objects opened in ELF_C_READ mode.

RETURN VALUES

     Function elf_cntl() returns 0 on success, or -1 if an error was detected.

ERRORS

     [ELF_E_ARCHIVE]   Argument elf is a descriptor for an archive member.

     [ELF_E_ARGUMENT]  Argument elf was NULL.

     [ELF_E_ARGUMENT]  Argument cmd was not recognized.

     [ELF_E_MODE]      An ELF_C_FDREAD operation was requested on an ELF descriptor opened for writing.

SEE ALSO

     elf(3), elf_begin(3), elf_end(3), elf_next(3), elf_update(3), gelf(3)

BSD
								  August 9, 2006							       BSD

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)