ldopen(3X)                                             ldopen(3X)



NAME
     ldopen, ldaopen - open a common object file for reading

SYNOPSIS
     #include <stdio.h>
     #include <filehdr.h>
     #include <ldfcn.h>

     LDFILE *ldopen (filename, ldptr)
     char *filename;
     LDFILE *ldptr;

     LDFILE *ldaopen (filename, oldptr)
     char *filename;
     LDFILE *oldptr;

DESCRIPTION
     ldopen and ldclose(3X) are designed to provide uniform
     access to both simple object files and object files that are
     members of archive files.  Thus an archive of common object
     files can be processed as if it were a series of simple com-
     mon object files.

     If ldptr has the value NULL, then ldopen will open filename
     and allocate and initialize the LDFILE structure, and return
     a pointer to the structure to the calling program.

     If ldptr is valid and if TYPE(ldptr) is the archive magic
     number, ldopen will reinitialize the LDFILE structure for
     the next archive member of filename.

     ldopen and ldclose(3X) are designed to work in concert.
     Ldclose will return FAILURE only when TYPE(ldptr) is the
     archive magic number and there is another file in the
     archive to be processed.  Only then should ldopen be called
     with the current value of ldptr.  In all other cases, in
     particular whenever a new filename is opened, ldopen should
     be called with a NULL ldptr argument.

     The following is a prototype for the use of ldopen and
     ldclose(3X).














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ldopen(3X)                                             ldopen(3X)



          /* for each filename to be processed */

          ldptr = NULL;
          do
          {
               if ( (ldptr = ldopen(filename, ldptr)) != NULL )
               {
                    /* check magic number */
                    /* process the file */
               }
          } while (ldclose(ldptr) == FAILURE );

     If the value of oldptr is not NULL, ldaopen will open
     filename anew and allocate and initialize a new LDFILE
     structure, copying the TYPE, OFFSET, and HEADER fields from
     oldptr.  Ldaopen returns a pointer to the new LDFILE struc-
     ture.  This new pointer is independent of the old pointer,
     oldptr.  The two pointers may be used concurrently to read
     separate parts of the object file.  For example, one pointer
     may be used to step sequentially through the relocation
     information, while the other is used to read indexed symbol
     table entries.

     Both ldopen and ldaopen open filename for reading.  Both
     functions return NULL if filename cannot be opened, or if
     memory for the LDFILE structure cannot be allocated.  A suc-
     cessful open does not insure that the given file is a common
     object file or an archived object file.

     The program must be loaded with the object file access rou-
     tine library libld.a.

SEE ALSO
     fopen(3S), ldclose(3X), ldfcn(4).





















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