Name
hdr - display selected parts of an object file
Syntax
hdr [ -dhmprsSt ] file ...
Description
hdr displays object file headers, symbol tables, and text or
data relocation records in ASCII formats. It also prints
out seek positions for the various segments in the object
file. A.out, x.out, and x.out segmented formats and
archives are understood.
The symbol table format consists of six fields. In a.out
formats the third field is missing. The first field is the
symbol's index or position in the symbol table, printed in
decimal. The index of the first entry is zero. The second
field is the type, printed in hexadecimal. The third field
is the s_seg field, printed in hexadecimal. The fourth
field is the symbol's value in hexadecimal. The fifth field
is a single character that represents the symbol's type as
in nm(CP), except C common is not recognized as a special
case of undefined. The last field is the symbol name.
If long form relocation is present, the format consists of
six fields. The first is the descriptor, printed in
hexadecimal. The second is the symbol ID or index, in
decimal. This field is used for external relocations as an
index into the symbol table. It should reference an
undefined symbol table entry. The third field is the
position, or offset, within the current segment at which
relocation is to take place; it is printed in hexadecimal.
The fourth field is the name of the segment referenced in
the relocation: text, data, bss, or EXT for external. The
fifth field is the size of relocation: byte, word (2 bytes),
or long. The last field will indicate, if present, that the
relocation is relative.
If short form relocation is present, the format consist of
three fields. The first field is the relocation command in
hexadecimal. The second field contains the name of the
segment referenced: text or data. The last field indicates
the size of relocation: word or long.
The hdr options are:
-d Prints the data relocation records.
-h Prints the object file header and extended header.
Each field in the header or extended header is
labeled. This is the default option.
-m Prints the text and data segments. This option is
similar to the -S option but only for text and data
segments.
-p Prints the seek positions as defined by macros in
the include file <a.out.h>.
-r Prints both text and data relocation records.
-s Prints the symbol table.
-S Prints the file segment table with a header. (Only
applicable to x.out segmented executable files.)
-t Prints the text relocation records.
See Also
a.out(F), nm(CP).
Notes
hdr is only for use with object files created under UNIX
type environments.
(printed 6/18/89)