section header for a common object file
Every common object file has a table of section headers
to specify the layout of the data within the file.
Each section within an object file has its own header.
The C structure appears below.
char s_name[SYMNMLEN]; /* section name */
long s_paddr; /* physical address */
long s_vaddr; /* virtual address */
long s_size; /* section size */
long s_scnptr; /* file ptr to raw data */
long s_relptr; /* file ptr to relocation */
long s_lnnoptr; /* file ptr to line numbers */
unsigned short s_nreloc; /* # reloc entries */
unsigned short s_nlnno; /* # line number entries */
long s_flags; /* flags */
File pointers are byte offsets into the file;
they can be used as the offset in a call to fseek (see
If a section is initialized, the file contains the actual bytes.
An uninitialized section is somewhat different.
It has a size, symbols defined in it, and symbols that refer to it.
But it can have no relocation entries, line numbers, or data.
Consequently, an uninitialized section has no raw data
in the object file, and the values for
s_nlnno are zero.
is not part of any
currently supported standard;
it was developed by UNIX System Laboratories, Inc. and
is used by permission.
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 02 June 2005