nm - list symbols from object files
SYNOPSIS
nm [ -a | --debug-syms ] [ -g | --extern-only ]
[ -B ] [ -C | --demangle[=style] ] [ -D | --dynamic ]
[ -s | --print-armap ] [ -A | -o | --print-file-name ]
[ -n | -v | --numeric-sort ] [ -p | --no-sort ]
[ -r | --reverse-sort ] [ --size-sort ] [ -u | --unde
fined-only ]
[ -t radix | --radix=radix ] [ -P | --portability ]
[ --target=bfdname ] [ -f format | --format=format ]
[ --defined-only ] [-l | --line-numbers ] [ --no-
demangle ]
[ -V | --version ] [ -X 32_64 ] [ --help ] [ obj
file... ]
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).
`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 unini
tialized data. When linking, multiple common sym
bols 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
`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 information; for more information, see
@ref{Top,Stabs,Stabs Overview,stabs.info, The
``stabs'' debug format}.
`?' The symbol type is unknown, or object file format
specific.
· The symbol name.
OPTIONS
The long and short forms of options, shown here as alter
natives, 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.
`--debug-syms '
Display all symbols, even debugger-only symbols; nor
mally 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.
`-l'
`--line-numbers'
For each symbol, use debugging information to try to
find a filename and line number. For a defined sym
bol, 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 sym
bol. If line number information can be found, print
`-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.
`-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.
`-r'
`--reverse-sort '
Reverse the order of the sort (whether numeric or
alphabetic); let the last come first.
`--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. 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 hex
adecimal.
`--target=bfdname'
Specify an object code format other than your system's
default format.
`--undefined-only '
Display only undefined symbols (those external to each
object file).
`--defined-only'
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' cor
responds 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 Documenta
tion License, Version 1.1 or any later version published
by the Free Software Foundation; with no Invariant Sec
tions, 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".
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