NAME
nm - list symbols from object files
SYNOPSIS
nm [-aï debugsyms] [-gï externonly]
[-B] [-Cï demangle[=style]] [-Dï dynamic]
[-sï printarmap] [-Aï-oï printfilename]
[-nï-vï numericsort] [-pï nosort]
[-rï reversesort] [ sizesort] [-uï undefinedonly]
[-t radixï radix=radix] [-Pï portability]
[ target=bfdname] [-fformatï format=format]
[ definedonly] [-lï linenumbers] [ nodemangle]
[-Vï version] [-X 32_64] [ help] [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:
· 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).
The symbol's value is absolute, and will not be changed by further linking. The symbol is
in the uninitialized data section (known as BSS). 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. The symbol is in the initialized data section. 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. 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. The symbol is a debugging symbol. The
symbol is in a read only data section. The symbol is in an uninitialized data section for
small objects. The symbol is in the text (code) section. The symbol is undefined. 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. 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 information. The symbol type is unknown, or object
file format specific.
· The symbol name.
OPTIONS
The long and short forms of options, shown here as alternatives, are equivalent.
-A
-o
printfilename
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
debugsyms
Display all symbols, even debuggeronly symbols; normally these are not listed.
-B The same as format=bsd (for compatibility with the MIPS nm).
-C
demangle[=style]
Decode (demangle) lowlevel symbol names into userlevel 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.
nodemangle
Do not demangle lowlevel 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
externonly
Display only external symbols.
-l
linenumbers
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
numericsort
Sort symbols numerically by their addresses, rather than alphabetically by their names.
-p
nosort
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.
-s
printarmap
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.
-r
reversesort
Reverse the order of the sort (whether numeric or alphabetic); let the last come first.
sizesort
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
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.
target=bfdname
Specify an object code format other than your system's default format.
-u
undefinedonly
Display only undefined symbols (those external to each object file).
definedonly
Display only defined symbols for 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.
help
Show a summary of the options to nm and exit.
SEE ALSO
ar (1), objdump (1), ranlib (1), and the Info entries for binutils.
COPYRIGHT
Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001 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 FrontCover Texts, and with no
BackCover Texts. A copy of the license is included in the section entitled ``GNU Free
Documentation License''.