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 rou-
          tine 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 pro-
          grams within libraries may be important.  If the first mem-
          ber 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 use-
               fulness 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 useful for

     LD(1)                                                       LD(1)

               loading wholly from a library, since initially the sym-
               bol table is empty and an unresolved reference is
               needed to force the loading of the 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 out-
               put 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 symbol' diagnos-
               tics.

          -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 boundary follow-
               ing 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.

     LD(1)                                                       LD(1)

     FILES
          /lib/lib*.a      libraries
          /usr/lib/lib*.a  more libraries
          a.out            output file

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

     BUGS