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   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 common object
          files.

          If ldptr has the value NUll, ldopen opens filename,
          allocates and initializes the LDFILE structure, and returns
          a pointer to the structure to the calling program.

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

          ldopen and ldclose are designed to work in concert.  ldclose
          returns 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.














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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 opens filename
          anew and allocates and initializes a new LDFILE structure,
          copying the TYPE, OFFSET, and HEADER fields from oldptr.
          ldaopen returns a pointer to the new LDFILE structure.  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
          successful 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
          routine library libld.a.

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






















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