Manual Pages for UNIX Operating System command usage for man elf_cntl

ELF Library Functions                              elf_cntl(3ELF)



NAME
     elf_cntl - control an elf file descriptor

SYNOPSIS
     cc [ flag ... ] file ... -lelf [ library ... ]
     #include 

     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 asso-
     ciated with an archive file, descriptors for members  within
     the archive 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 pro-
                     gram 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 section,  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 descrip-
                     tor 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.







SunOS 5.11          Last change: 11 Jul 2001                    1






ELF Library Functions                              elf_cntl(3ELF)



     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  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | 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 opera-
     tions explicitly beforehand. Otherwise, the raw file  opera-
     tions  will  fail.  Calling  elf_rawfile()  makes the entire
     image available, thus  supporting  subsequent  elf_rawdata()
     calls.
























SunOS 5.11          Last change: 11 Jul 2001                    2