nm − list symbols from object files

nm [−a−−debug−syms] [−g−−extern−only]
   [−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 local; if
    uppercase, the symbol is global (external).

    "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" The symbol is an indirect reference to another
        symbol.  This is a GNU extension to the a.out object
        file format which is rarely used.

    "N" The symbol is a debugging symbol.


    "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.

    "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.

    "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 weak
        symbol becomes zero with no error.

    "−" 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.


    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 size of defined symbols for the "bsd" output


    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.  The size of
    the symbol is printed, rather than the value.

−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.

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

Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
2001, 2002 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify
this document under the terms of the GNU Free Documentation
License, Version 1.1 or any later version published by the
Free Software Foundation; with no Invariant Sections, with
no Front‐Cover Texts, and with no Back‐Cover Texts.  A copy
of the license is included in the section entitled "GNU Free
Documentation License".