filehdr(5) File Formats Manual filehdr(5) Name filehdr - file header for RISC object files Syntax #include < filehdr.h> Description Every RISC 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 pointer to symbolic header */ long f_nsyms; /* sizeof(symbolic header) */ unsigned short f_opthdr; /* sizeof(optional header) */ unsigned short f_flags; /* flags */ }; The byte offset into the file at which the symbolic header can be found is f_symptr. Its value can be used as the offset in to position an I/O stream to the symbolic header. The ULTRIX system optional header is 56 bytes. The valid magic numbers are given below: #define MIPSEBMAGIC 0x0160 /* objects for big-endian machines */ #define MIPSELMAGIC 0x0162 /* objects for little-endian machines */ #define MIPSEBUMAGIC 0x0180 /* ucode objects for big-endian machines */ #define MIPSELUMAGIC 0x0182 /* ucode objects for little-endian machines */ RISC object files can be loaded and examined on machines differing from the object's target byte sex. Therefore, for object file magic numbers, the byte-swapped values have define constants associated with them: #define SMIPSEBMAGIC 0x6001 #define SMIPSELMAGIC 0x6201 The value in f_timdat is obtained from the system call. Flag bits used in RISC objects are: #define F_RELFLG 0000001 /* relocation entries stripped */ #define F_EXEC 0000002 /* file is executable */ #define F_LNNO 0000004 /* line numbers stripped */ #define F_LSYMS 0000010 /* local symbols stripped */ See Also time(2), fseek(3s), a.out(5) RISC filehdr(5)