nm - list symbols from object files
nm [-a|--debug-syms] [-g|--extern-only]
[-B] [-C|--demangle[=style]] [-D|--dynamic]
[-r|--reverse-sort] [--size-sort] [-u|--undefined-only]
[-t radix|--radix=radix] [-P|--portability]
[--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 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).
"A" The symbol's value is absolute, and will not be changed by fur-
"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 array.
"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
"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
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 information.
"?" The symbol type is unknown, or object file format specific.
· The symbol name.
The long and short forms of options, shown here as alternatives, are
Precede each symbol by the name of the input file (or archive mem-
ber) in which it was found, rather than identifying the input file
once only, before all of its symbols.
Display all symbols, even debugger-only symbols; normally these are
-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 com-
Do not demangle low-level symbol names. This is the default.
Display the dynamic symbols rather than the normal symbols. This
is only meaningful for dynamic objects, such as certain types of
Use the output format format, which can be "bsd", "sysv", or
For each symbol, use debugging information to try to find a file-
name and line number. For a defined symbol, look for the line num-
ber of the address of the symbol. For an undefined symbol, look
for the line number of a relocation entry which refers to the sym-
bol. If line number information can be found, print it after the
other symbol information.
Sort symbols numerically by their addresses, rather than alphabeti-
cally by their names.
Do not bother to sort the symbols in any order; print them in the
Use the POSIX.2 standard output format instead of the default for-
mat. Equivalent to -f posix.
Print size, not the value, 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. 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.
Use radix as the radix for printing the symbol values. It must be
d for decimal, o for octal, or x for hexadecimal.
Specify an object code format other than your system's default for-
-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 binutils.
Copyright (c) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
2003 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''.
binutils-030512 2003-05-12 nm(1)