NMEDIT(1) NMEDIT(1)

NAME
       nmedit - change global symbols to local symbols

SYNOPSIS
       nnmmeeddiitt  -s  listfile  [-R  listfile] [-p] [-A] [-] [[-arch archtype]
       ...] objectfile ... [-o output]

DESCRIPTION
       Nmedit changes the global symbols not listed in the listfile  file  of
       the  -ss listfile option to static symbols.  Undefined symbols and com-
       mon symbols are not affected and shouldn't be listed in listfile.  For
       dynamic  libraries  symbols are turned into private extern symbols that
       are no longer external (rather than static symbols).  This is  done  so
       that  the  references between modules of a dynamic library are resolved
       to the symbols in the dynamic library.  Nmedit differs from strip(1) in
       that it also changes the symbolic debugging information (produce by the
       -gg option to cc(1)) for the global symbols it changes to static symbols
       so that the resulting object can still be used with the debugger.

       Nmedit  like strip(1) is useful to limit the symbols for use with later
       linking.  This allows control of  the  interface  that  the  executable
       wants  to  provide to the objects that it will dynamically load, and it
       will not have to publish symbols that are not part  of  its  interface.
       For  example  an  executable  that wishes to allow only a subset of its
       global symbols but all of the shared libraries globals to be used would
       have its symbol table edited with:
              % nmedit -s interfacesymbols -A executable
       where  the file interfacesymbols would contain only those symbols from
       the executable that it wishes the objects loaded  at  runtime  to  have
       access to.  Another example is an object that is made up of a number of
       other objects that will be loaded into an executable  would  built  and
       then have its symbol table edited with:
              % ld -o relocatable.o -r a.o b.o c.o
              % nmedit -s interfacesymbols relocatable.o
       which would leave only the symbols listed in the file interfacesymbols
       (and the undefined and common symbols) as global symbols in the  object
       file.

       The one or more of the following options is required to nmedit(1) is:

       -ss filename
              Leave  the symbol table entries for the global symbols listed in
              filename global but turn all other global symbols (except  unde-
              fined and common symbols) into static symbols.  The symbol names
              listed in filename must be one per line.  Leading  and  trailing
              white  space  are  not  part of the symbol name.  Lines starting
              with # are ignored, as are lines with only white space.

       -RR filename
              Change the symbol table entries for the global symbols listed in
              filename  into static symbols.  This file has the same format as
              the -ss filename option above.  If  the  -RR  filename  option  is
              specified  without  the -ss filename option, then all symbols not
              listed in the -RR filename option's filename are left as globals.
              If  both  a  -RR filename and a -ss filename are given the symbols
              listed in the -RR filename are basically ignored and  only  those
              symbols listed in the -ss filename are saved.

       -pp     Change  symbols  to  private externs instead of static.  This is
              allowed as the only option to change all defined global  symbols
              to private externs.

       The options to nmedit(1) are:

       -AA     Leave  all  global absolute symbols except those with a value of
              zero, and save objective-C class symbols as  globals.   This  is
              intended  for use of programs that load code at runtime and want
              the loaded code to use symbols from the shared libraries.

       -      Treat all remaining arguments as file names and not options.

       -aarrcchh archtype
              Specifies the architecture, archtype, of the file for nmedit(1)
              to  process  when  the file is a universal file (see arch(3) for
              the currently know archtypes).  The archtype  can  be  all  to
              process  all  architectures  in  the  file.   The  default is to
              process all architectures that are contained in the file.

       -oo output
              Write the result into the file output.

SEE ALSO
       strip(1), ld(1), arch(3)

BUGS
       The changing of the symbolic debugging information  by  nmedit  is  not
       known  to be totally correct and could cause the debugger to crash, get
       confused or produce incorrect information.



Apple Inc.                       May 29, 2007                        NMEDIT(1)