elf_getscn(3E)                                        elf_getscn(3E)


       NAME
             elf_getscn, elf_ndxscn, elf_newscn, elf_nextscn - get section
             information

       SYNOPSIS
             cc [flag . . . ] file . . . -lelf [library] . . .
             #include <libelf.h>
             Elf_Scn *elf_getscn(Elf *elf, size_t index);
             size_t elf_ndxscn(Elf_Scn *scn);
             Elf_Scn *elf_newscn(Elf *elf);
             Elf_Scn *elf_nextscn(Elf *elf, Elf_Scn *scn);

       DESCRIPTION
             These functions provide indexed and sequential access to the
             sections associated with the ELF descriptor elf.  If the
             program is building a new file, it is responsible for creating
             the file's ELF header before creating sections; see
             elf_getehdr(3E).

             elf_getscn returns a section descriptor, given an index into
             the file's section header table.  Note the first ``real''
             section has index 1.  Although a program can get a section
             descriptor for the section whose index is 0 (SHN_UNDEF, the
             undefined section), the section has no data and the section
             header is ``empty'' (though present).  If the specified
             section does not exist, an error occurs, or elf is null,
             elf_getscn returns a null pointer.

             elf_newscn creates a new section and appends it to the list
             for elf.  Because the SHN_UNDEF section is required and not
             ``interesting'' to applications, the library creates it
             automatically.  Thus the first call to elf_newscn for an ELF
             descriptor with no existing sections returns a descriptor for
             section 1.  If an error occurs or elf is null, elf_newscn
             returns a null pointer.

             After creating a new section descriptor, the program can use
             elf_getshdr to retrieve the newly created, ``clean'' section
             header.  The new section descriptor will have no associated
             data [see elf_getdata(3E)].  When creating a new section in
             this way, the library updates the e_shnum member of the ELF
             header and sets the ELF_F_DIRTY bit for the section [see
             elf_flag(3E)].  If the program is building a new file, it is
             responsible for creating the file's ELF header [see
             elf_getehdr(3E)] before creating new sections.



                           Copyright 1994 Novell, Inc.               Page 1

      elf_getscn(3E)                                        elf_getscn(3E)


            elf_nextscn takes an existing section descriptor, scn, and
            returns a section descriptor for the next higher section.  One
            may use a null scn to obtain a section descriptor for the
            section whose index is 1 (skipping the section whose index is
            SHN_UNDEF).  If no further sections are present or an error
            occurs, elf_nextscn returns a null pointer.

            elf_ndxscn takes an existing section descriptor, scn, and
            returns its section table index.  If scn is null or an error
            occurs, elf_ndxscn returns SHN_UNDEF.

      EXAMPLES
            An example of sequential access appears below.  Each pass
            through the loop processes the next section in the file; the
            loop terminates when all sections have been processed.

                 scn = 0;
                 while ((scn = elf_nextscn(elf, scn)) != 0)
                 {
                         /* process section */
                 }

      REFERENCES
            elf(3E), elf_begin(3E), elf_flag(3E), elf_getdata(3E),
            elf_getehdr(3E), elf_getshdr(3E)























                          Copyright 1994 Novell, Inc.               Page 2