ELF Library Functions                              elfcntl(3ELF)



NAME
     elfcntl - control an elf file descriptor

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

     int elfcntl(Elf *elf, ElfCmd cmd);


DESCRIPTION
     elfcntl() instructs the library to modify its behavior with
     respect  to  an  ELF  descriptor,  elf.  As  elfbegin(3ELF)
     describes, an ELF descriptor can have multiple  activations,
     and  multiple  ELF  descriptors  may  share  a  single  file
     descriptor. Generally,  elfcntl()  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:

     ELFCFDONE    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
                     elfgetdata() for a section,  will  fail  if
                     the data are not in memory already.


     ELFCFDREAD    This command  is  similar  to  ELFCFDONE,
                     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 elfcntl() completes
                     the ELFCFDREAD command, future operations,
                     such  as  elfgetdata(), 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                              elfcntl(3ELF)



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

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Stable                      
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     elf(3ELF),        elfbegin(3ELF),        elfgetdata(3ELF),
     elfrawfile(3ELF), libelf(3LIB), attributes(5)

NOTES
     If the program wishes to use  the  ``raw''  operations  (see
     elfrawdata(),   which   elfgetdata(3ELF)   describes,  and
     elfrawfile(3ELF)) after disabling the file descriptor  with
     ELFCFDONE or ELFCFDREAD, it must execute the raw opera-
     tions explicitly beforehand. Otherwise, the raw file  opera-
     tions  will  fail.  Calling  elfrawfile()  makes the entire
     image available, thus  supporting  subsequent  elfrawdata()
     calls.
























SunOS 5.11          Last change: 11 Jul 2001                    2