nm − list symbols from object files

nm [−a|−−debug−syms]
   [−g|−−extern−only][−−plugin name]
   [−B] [−C|−−demangle[=style]] [−D|−−dynamic]
   [−S|−−print−size] [−s|−−print−armap]
   [−n|−v|−−numeric−sort] [−p|−−no−sort]
   [−r|−−reverse−sort] [−−size−sort] [−u|−−undefined−only]
   [−t radix|−−radix=radix] [−P|−−portability]
   [−−target=bfdname] [−fformat|−−format=format]
   [−−defined−only] [−l|−−line−numbers] [−−no−demangle]
   [−V|−−version] [−X 32_64] [−−help]  [objfile...]

GNU nm lists the symbols from object files objfile....  If
no object files are listed as arguments, nm assumes the file

     For each symbol, nm shows:

•   The symbol value, in the radix selected by options (see
    below), or hexadecimal by default.

•   The symbol type.  At least the following types are used;
    others are, as well, depending on the object file
    format.  If lowercase, the symbol is usually local; if
    uppercase, the symbol is global (external).  There are
    however a few lowercase symbols that are shown for
    special global symbols ("u", "v" and "w").

    "A" The symbol’s value is absolute, and will not be
        changed by further linking.


    "b" The symbol is in the uninitialized data section
        (known as BSS).

    "C" The symbol is common.  Common symbols are
        uninitialized data.  When linking, multiple common
        symbols may appear with the same name.  If the
        symbol is defined anywhere, the common symbols are
        treated as undefined references.


    "d" The symbol is in the initialized data section.


    "g" The symbol is in an initialized data section for
        small objects.  Some object file formats permit more
        efficient access to small data objects, such as a
        global int variable as opposed to a large global



    "i" For PE format files this indicates that the symbol
        is in a section specific to the implementation of
        DLLs.  For ELF format files this indicates that the
        symbol is an indirect function.  This is a GNU
        extension to the standard set of ELF symbol types.
        It indicates a symbol which if referenced by a
        relocation does not evaluate to its address, but
        instead must be invoked at runtime.  The runtime
        execution will then return the value to be used in
        the relocation.

    "N" The symbol is a debugging symbol.

    "p" The symbols is in a stack unwind section.


    "r" The symbol is in a read only data section.


    "s" The symbol is in an uninitialized data section for
        small objects.


    "t" The symbol is in the text (code) section.

    "U" The symbol is undefined.

    "u" The symbol is a unique global symbol.  This is a GNU
        extension to the standard set of ELF symbol
        bindings.  For such a symbol the dynamic linker will
        make sure that in the entire process there is just
        one symbol with this name and type in use.


    "v" The symbol is a weak object.  When a weak defined
        symbol is linked with a normal defined symbol, the
        normal defined symbol is used with no error.  When a
        weak undefined symbol is linked and the symbol is
        not defined, the value of the weak symbol becomes
        zero with no error.  On some systems, uppercase
        indicates that a default value has been specified.


    "w" The symbol is a weak symbol that has not been
        specifically tagged as a weak object symbol.  When a
        weak defined symbol is linked with a normal defined
        symbol, the normal defined symbol is used with no


        error.  When a weak undefined symbol is linked and
        the symbol is not defined, the value of the symbol
        is determined in a system‐specific manner without
        error.  On some systems, uppercase indicates that a
        default value has been specified.

    "−" The symbol is a stabs symbol in an a.out object
        file.  In this case, the next values printed are the
        stabs other field, the stabs desc field, and the
        stab type.  Stabs symbols are used to hold debugging

    "?" The symbol type is unknown, or object file format

•   The symbol name.

The long and short forms of options, shown here as
alternatives, are equivalent.



    Precede each symbol by the name of the input file (or
    archive member) in which it was found, rather than
    identifying the input file once only, before all of its


    Display all symbols, even debugger‐only symbols;
    normally these are not listed.

−B  The same as −−format=bsd (for compatibility with the
    MIPS nm).


    Decode (demangle) low‐level symbol names into user‐level
    names.  Besides removing any initial underscore
    prepended by the system, this makes C++ function names
    readable. Different compilers have different mangling
    styles. The optional demangling style argument can be
    used to choose an appropriate demangling style for your

    Do not demangle low‐level symbol names.  This is the



    Display the dynamic symbols rather than the normal
    symbols.  This is only meaningful for dynamic objects,
    such as certain types of shared libraries.

−f format

    Use the output format format, which can be "bsd",
    "sysv", or "posix".  The default is "bsd".  Only the
    first character of format is significant; it can be
    either upper or lower case.


    Display only external symbols.

−−plugin name
    Load the plugin called name to add support for extra
    target types.  This option is only available if the
    toolchain has been built with plugin support enabled.


    For each symbol, use debugging information to try to
    find a filename and line number.  For a defined symbol,
    look for the line number of the address of the symbol.
    For an undefined symbol, look for the line number of a
    relocation entry which refers to the symbol.  If line
    number information can be found, print it after the
    other symbol information.



    Sort symbols numerically by their addresses, rather than
    alphabetically by their names.


    Do not bother to sort the symbols in any order; print
    them in the order encountered.


    Use the POSIX.2 standard output format instead of the


    default format.  Equivalent to −f posix.


    Print both value and size of defined symbols for the
    "bsd" output style.  This option has no effect for
    object formats that do not record symbol sizes, unless
    −−size−sort is also used in which case a calculated size
    is displayed.


    When listing symbols from archive members, include the
    index: a mapping (stored in the archive by ar or ranlib)
    of which modules contain definitions for which names.


    Reverse the order of the sort (whether numeric or
    alphabetic); let the last come first.

    Sort symbols by size.  The size is computed as the
    difference between the value of the symbol and the value
    of the symbol with the next higher value.  If the "bsd"
    output format is used the size of the symbol is printed,
    rather than the value, and −S must be used in order both
    size and value to be printed.

    Display symbols which have a target‐specific special
    meaning.  These symbols are usually used by the target
    for some special processing and are not normally helpful
    when included included in the normal symbol lists.  For
    example for ARM targets this option would skip the
    mapping symbols used to mark transitions between ARM
    code, THUMB code and data.

−t radix

    Use radix as the radix for printing the symbol values.
    It must be d for decimal, o for octal, or x for

    Specify an object code format other than your system’s
    default format.



    Display only undefined symbols (those external to each
    object file).

    Display only defined symbols for each object file.


    Show the version number of nm and exit.

−X  This option is ignored for compatibility with the AIX
    version of nm.  It takes one parameter which must be the
    string 32_64.  The default mode of AIX nm corresponds to
    −X 32, which is not supported by GNU nm.

    Show a summary of the options to nm and exit.

    Read command‐line options from file.  The options read
    are inserted in place of the original @file option.  If
    file does not exist, or cannot be read, then the option
    will be treated literally, and not removed.

    Options in file are separated by whitespace.  A
    whitespace character may be included in an option by
    surrounding the entire option in either single or double
    quotes.  Any character (including a backslash) may be
    included by prefixing the character to be included with
    a backslash.  The file may itself contain additional
    @file options; any such options will be processed

ar(1), objdump(1), ranlib(1), and the Info entries for

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