filehdr(4)                                             filehdr(4)



     NAME
          filehdr - file header for common object files

     SYNOPSIS
          #include <filehdr.h>

     DESCRIPTION
          Every common object file begins with a 20-byte header.  The
          following C struct declaration is used:

          struct    filehdr
          {
             unsigned short     f_magic ;   /* magic number */
             unsigned short     f_nscns ;   /* number of sections */
             long               f_timdat ;  /* time & date stamp */
             long               f_symptr ;  /* file ptr to symtab */
             long               f_nsyms ;   /* # symtab entries */
             unsigned short     f_opthdr ;  /* sizeof(opt hdr) */
             unsigned short     f_flags ;   /* flags */
          } ;



          fsymptr is the byte offset into the file at which the
          symbol table can be found.  Its value can be used as the
          offset in fseek(3S) to position an I/O stream to the symbol
          table.  See aouthdr(4) for the structure of the optional
          aout header.  The valid magic number is:

          #define   MC68MAGIC   0520    /*  magic number */

          The value in ftimdat is obtained from the time(2) system
          call.  Flag bits currently defined are:

          #define F_RELFLG  00001 /* relocation entries stripped */
          #define F_EXEC    00002 /* file is executable */
          #define F_LNNO    00004 /* line numbers stripped */
          #define F_LSYMS   00010 /* local symbols stripped */
          #define F_MINMAL  00020 /* minimal object file */
          #define F_UPDATE  00040 /* update file, ogen produced */
          #define F_SWABD   00100 /* file is "pre-swabbed" */
          #define F_AR16WR  00200 /* 16-bit DEC host */
          #define F_AR32WR  00400 /* 32-bit DEC host */
          #define F_AR32W   01000 /* non-DEC host */
          #define F_PATCH   02000 /* "patch" list in opt hdr */

     SEE ALSO
          time(2), fseek(3S), a.out(4), aouthdr(4).







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