nm(1) [opendarwin man page]
NM(1) General Commands Manual NM(1) NAME
nm - display name list (symbol table) SYNOPSIS
nm [ -agnoprumxjlf [ s segname sectname ]] [ file ... ] DESCRIPTION
Nm displays the name list (symbol table) of each object file in the argument list. If an argument is an archive, a listing for each object file in the archive will be produced. File can be of the form libx.a(x.o), in which case only symbols from that member of the object file are listed. (The parentheses have to be quoted to get by the shell.) If no file is given, the symbols in a.out are listed. Each symbol name is preceded by its value (blanks if undefined). Unless the -m option is specified, this value is followed by one of the following characters, representing the symbol type: U (undefined), A (absolute), T (text section symbol), D (data section symbol), B (bss section symbol), C (common symbol), - (for debugger symbol table entries; see -a below), S (symbol in a section other than those above), or I (indirect symbol). If the symbol is local (non-external), the symbol's type is instead represented by the corresponding lowercase let- ter. A lower case u in a dynamic shared library indicates a undefined reference to a private external in another module in the same library. If the symbol is a Objective C method, the symbol name is +-[Class_name(category_name) method:name:], where `+' is for class methods, `-' is for instance methods, and (category_name) is present only when the method is in a category. The output is sorted alphabetically by default. Options are: -a Display all symbol table entries, including those inserted for use by debuggers. -g Display only global (external) symbols. -n Sort numerically rather than alphabetically. -o Prepend file or archive element name to each output line, rather than only once. -p Don't sort; display in symbol-table order. -r Sort in reverse order. -u Display only undefined symbols. -m Display the N_SECT type symbols (Mach-O symbols) as (segment_name, section_name) followed by either external or non-external and then the symbol name. Undefined, common, absolute and indirect symbols get displayed as (undefined), (common), (absolute), and (indirect), respectively. -x Display the symbol table entry's fields in hexadecimal, along with the name as a string. -j Just display the symbol names (no value or type). -s segname sectname List only those symbols in the section (segname,sectname). -l List a pseudo symbol .section_start if no symbol has as its value the starting address of the section. (This is used with the -s option above.) -arch arch_type Specifies the architecture, arch_type, of the file for nm(1) to operate on when the file is a fat file (see arch(3) for the cur- rently known arch_types). The arch_type can be "all" to operate on all architectures in the file. The default is to display the symbols from only the host architecture, if the file contains it; otherwise, symbols for all architectures in the file are dis- played. -f Display the symbol table of a dynamic library flat (as one file not separate modules). SEE ALSO
ar(1), ar(5), Mach-O(5), stab(5), nlist(3) BUGS
Displaying Mach-O symbols with -m is too verbose. Without the -m, symbols in the Objective C sections get displayed as an `s'. Apple Computer, Inc. October 23, 1997 NM(1)
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NMEDIT(1) General Commands Manual NMEDIT(1) NAME
nmedit - change global symbols to local symbols SYNOPSIS
nmedit -s list_file [-R list_file] [-p] [-A] [-] [[-arch arch_type] ...] object_file ... [-o output] DESCRIPTION
Nmedit changes the global symbols not listed in the list_file file of the -s list_file option to static symbols. Undefined symbols and common symbols are not effected and shouldn't be listed in list_file. 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 -g 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 interface_symbols -A executable where the file interface_symbols 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 interface_symbols relocatable.o which would leave only the symbols listed in the file interface_symbols (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: -s filename Leave the symbol table entries for the global symbols listed in filename global but turn all other global symbols (except undefined 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. -R filename Change the symbol table entries for the global symbols listed in filename into static symbols. This file has the same format as the -s filename option above. If the -R filename option is specified without the -s filename option, then all symbols not listed in the -R filename option's filename are left as globals. If both a -R filename and a -s filename are given the symbols listed in the -R filename are basically ignored and only those symbols listed in the -s filename are saved. -p 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: -A 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. -arch arch_type Specifies the architecture, arch_type, of the file for nmedit(1) to process when the file is a fat file (see arch(3) for the cur- rently know arch_types). The arch_type can be all to process all architectures in the file. The default is to process all archi- tectures that are contained in the file. -o 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 Computer, Inc. March 19, 2002 NMEDIT(1)