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ELF_GETSCN(3)              Library Functions Manual              ELF_GETSCN(3)

NAME
     elf_getscn, elf_ndxscn, elf_newscn, elf_nextscn - get/allocate section
     information for an ELF object

LIBRARY
     ELF Access Library (libelf, -lelf)

SYNOPSIS
     #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 are used to iterate through the sections associated with
     an ELF descriptor.

     Function elf_getscn() will return a section descriptor for the section at
     index index in the object denoted by ELF descriptor elf.  An error will
     be signalled if the specified section does not exist.

     Function elf_ndxscn() returns the section table index associated with
     section descriptor scn.

     Function elf_newscn() creates a new section and appends it to the list of
     sections associated with descriptor elf.  The library will automatically
     increment the e_shnum field of the ELF header associated with descriptor
     elf, and will set the ELF_F_DIRTY flag on the returned section
     descriptor.  For ELF descriptors opened for writing, the ELF library will
     automatically create an empty section at index zero (SHN_UNDEF) on the
     first call to elf_newscn().

     Function elf_nextscn() takes a section descriptor scn and returns a
     pointer to the section descriptor at the next higher index.  As a
     consequence, elf_nextscn() will never return a pointer to the empty
     section at index zero (SHN_UNDEF).  Argument scn is allowed to be NULL,
     in which case this function will return a pointer to the section
     descriptor at index 1.  If no further sections are present, function
     elf_nextscn() will return a NULL pointer.

RETURN VALUES
     Functions elf_getscn(), elf_newscn() and elf_nextscn() return a valid
     pointer to a section descriptor if successful, or NULL if an error
     occurs.

     Function elf_ndxscn() returns a valid section table index if successful,
     or SHN_UNDEF if an error occurs.

ERRORS
     These functions may fail with the following errors:

     [ELF_E_ARGUMENT]  Arguments elf or scn were NULL.

     [ELF_E_ARGUMENT]  Argument index exceeded the current number of sections
                       in the ELF object.

     [ELF_E_ARGUMENT]  Argument elf was not a descriptor for an ELF file.

     [ELF_E_ARGUMENT]  Section descriptor scn was not associated with ELF
                       descriptor elf.

     [ELF_E_CLASS]     Descriptor elf was of an unknown ELF class.

     [ELF_E_SECTION]   Argument elf specified extended section numbering in
                       the ELF header with the section header at index
                       SHN_UNDEF not being of type SHT_NULL.

SEE ALSO
     elf(3), elf_flagdata(3), elf_flagscn(3), elf_getdata(3), elf_getshdr(3),
     gelf(3)

NetBSD 10.99                  September 24, 2018                  NetBSD 10.99