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CentOS 7.0 - man page for nm (centos section 1)

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NM(1)				      GNU Development Tools				    NM(1)

NAME
       nm - list symbols from object files

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

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

       For each symbol, nm shows:

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

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

	   "G"
	   "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 array.

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

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

	   "T"
	   "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"
	   "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"
	   "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 information.

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

       o   The symbol name.

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

       -A
       -o
       --print-file-name
	   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 symbols.

       -a
       --debug-syms
	   Display all symbols, even debugger-only symbols; normally these are not listed.

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

       -C
       --demangle[=style]
	   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 compiler.

       --no-demangle
	   Do not demangle low-level symbol names.  This is the default.

       -D
       --dynamic
	   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
       --format=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.

       -g
       --extern-only
	   Display only external symbols.

       -h
       --help
	   Show a summary of the options to nm and exit.

       -l
       --line-numbers
	   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.

       -n
       -v
       --numeric-sort
	   Sort symbols numerically by their addresses, rather than alphabetically by their
	   names.

       -p
       --no-sort
	   Do not bother to sort the symbols in any order; print them in the order encountered.

       -P
       --portability
	   Use the POSIX.2 standard output format instead of the default format.  Equivalent to
	   -f posix.

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

       -S
       --print-size
	   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.

       -s
       --print-armap
	   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.

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

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

       -V
       --version
	   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.

       --defined-only
	   Display only defined symbols for each object file.

       --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.

       --size-sort
	   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.

       --special-syms
	   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.

       --synthetic
	   Include synthetic symbols in the output.  These are special symbols created by the
	   linker for various purposes.  They are not shown by default since they are not part of
	   the binary's original source code.

       --target=bfdname
	   Specify an object code format other than your system's default format.

       @file
	   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 recursively.

SEE ALSO
       ar(1), objdump(1), ranlib(1), and the Info entries for binutils.

COPYRIGHT
       Copyright (c) 1991-2013 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 1.3 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".

binutils-2.23.52.0.1			    2014-06-10					    NM(1)


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