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LD(1)							    LD(1)

NAME
       ld - loader

SYNOPSIS
       ld [ option ] file ...

DESCRIPTION
       Ld  combines  several  object  programs into one, resolves
       external references, and searches libraries.  In the  sim-
       plest case several object files are given, and ld combines
       them, producing an object module which can be either  exe-
       cuted  or  become the input for a further ld run.  (In the
       latter case, the -r option must be given to  preserve  the
       relocation  bits.)   The	 output	 of  ld is left on a.out.
       This file is made executable only if  no	 errors	 occurred
       during the load.

       The argument routines are concatenated in the order speci-
       fied.  The entry point of the output is the  beginning  of
       the first routine.

       If  any argument is a library, it is searched exactly once
       at the point it is encountered in the argument list.  Only
       those  routines	defining an unresolved external reference
       are loaded.   If	 a  routine  from  a  library  references
       another	routine	 in  the library, and the library has not
       been processed by ranlib(1), the referenced  routine  must
       appear after the referencing routine in the library.  Thus
       the order of programs within libraries may  be  important.
       If  the	first  member  of a library is named `__.SYMDEF',
       then it is understood to be a dictionary for  the  library
       such  as	 produced  by  ranlib; the dictionary is searched
       iteratively to satisfy as many references as possible.

       The  symbols  `_etext',	`_edata'  and  `_end'	(`etext',
       `edata'	and `end' in C) are reserved, and if referred to,
       are set to the first location above the program, the first
       location	 above	initialized  data, and the first location
       above all data respectively.  It is  erroneous  to  define
       these symbols.

       Ld  understands	several	 options.   Except  for	 -l, they
       should appear before the file names.

       -s     `Strip' the output,  that	 is,  remove  the  symbol
	      table and relocation bits to save space (but impair
	      the usefulness of the debugger).	This  information
	      can also be removed by strip(1).

       -u     Take  the	 following argument as a symbol and enter
	      it as undefined in the symbol table.  This is  use-
	      ful  for	loading wholly from a library, since ini-
	      tially the symbol table is empty and an  unresolved
	      reference	 is  needed  to	 force the loading of the

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LD(1)							    LD(1)

	      first routine.

       -lx    This option is an abbreviation for the library name
	      `/lib/libx.a',  where  x is a string.  If that does
	      not exist, ld tries `/usr/lib/libx.a'.   A  library
	      is  searched  when  its name is encountered, so the
	      placement of a -l is significant.

       -x     Do not preserve local (non-.globl) symbols  in  the
	      output  symbol  table; only enter external symbols.
	      This option saves some space in the output file.

       -X     Save local symbols except	 for  those  whose  names
	      begin  with  `L'.	  This option is used by cc(1) to
	      discard internally generated labels while retaining
	      symbols local to routines.

       -r     Generate relocation bits in the output file so that
	      it can be the subject of another ld run.	This flag
	      also prevents final definitions from being given to
	      common symbols, and suppresses the `undefined  sym-
	      bol' diagnostics.

       -d     Force  definition	 of common storage even if the -r
	      flag is present.

       -n     Arrange that when the output file is executed,  the
	      text portion will be read-only and shared among all
	      users executing the file.	 This involves moving the
	      data  areas up to the first possible 4K word bound-
	      ary following the end of the text.

       -i     When the output file is executed, the program  text
	      and  data	 areas	will  live  in	separate  address
	      spaces.  The only difference  between  this  option
	      and  -n is that here the data starts at location 0.

       -o     The name argument after -o is used as the	 name  of
	      the ld output file, instead of a.out.

       -e     The  following  argument is taken to be the name of
	      the entry point of the loaded program;  location	0
	      is the default.

       -O     This is an overlay file, only the text segment will
	      be replaced by exec(2).  Shared data must have  the
	      same layout as in the program overlaid.

       -D     The next argument is a decimal number that sets the
	      size of the data segment.

FILES
       /lib/lib*.a	libraries
       /usr/lib/lib*.a	more libraries

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LD(1)							    LD(1)

       a.out		output file

SEE ALSO
       as(1), ar(1), cc(1), ranlib(1)

BUGS

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