nm —
display
symbolic information in object files
| nm |
[--debug-syms]
[--defined-only]
[--demangle[=style]]
[--dynamic]
[--extern-only]
[--help]
[--line-numbers]
[--no-demangle]
[--no-sort]
[--numeric-sort]
[--print-armap]
[--print-file-name]
[--print-size]
[--radix=format]
[--reverse-sort]
[--size-sort]
[--undefined-only]
[--version]
[-A]
[-B]
[-C
[style]]
[-D]
[-P]
[-V]
[-a]
[-e]
[-g]
[-h]
[-l]
[-n]
[-o]
[-p]
[-r]
[-S]
[-s]
[-t
format]
[-u]
[-x]
file ... |
The
nm utility displays symbolic information in the
object files, executables, and object library files named by its arguments.
Lack of symbolic information in an otherwise valid input file, is not
considered to be an error. If no files are specified on the command line,
nm will attempt to read
a.out.
The
nm utility recognizes the following options:
-
-
- --debug-syms
- Display all symbols, including debugger-only symbols.
-
-
- --defined-only
- Display only defined symbols.
-
-
- --demangle[=style]
- Decode (demangle) low-level symbol names into
human-readable names. Supported values for argument
style are ‘auto’,
‘gnu-v2’, ‘gnu-v3’ and ‘arm.’ If
argument style is not specified, it is
taken to be ‘auto’.
-
-
- --dynamic
- Only display dynamic symbols. This option is only
meaningful for shared libraries.
-
-
- --extern-only
- Only display information about global (external)
symbols.
-
-
- --help
- Display a help message and exit.
-
-
- --format=format
- Display output in the format specified by argument
format. Supported values for the format
argument are ‘bsd’, ‘sysv’, and
‘posix’. The default output format is
‘bsd’.
-
-
- --line-numbers
- Display the filename and line number associated a symbol
using any debugging information present in the input file. For defined
symbols, look up the line number associated with the address of the
symbol. For undefined symbols, look up the line number associated with a
relocation entry that refers to the symbol. If line number information can
be determined, it is displayed after other symbol information.
-
-
- --no-demangle
- Do not demangle symbol names (default).
-
-
- --no-sort
- Do not sort symbols.
-
-
- --numeric-sort
- Sort symbols numerically by address instead of
alphabetically by name.
-
-
- --print-armap
- For ar(1)
archives, include the index of the archive's members.
-
-
- --print-file-name
- Write the full pathname or library name of an object on
each line, before the rest of the information for a symbol. If this option
is not specified, nm will only identify an
input file once, before its symbols are listed.
-
-
- --print-size
- Print the size of each symbol instead of its value.
-
-
- --radix=radix
- Print numeric values using the specified radix. Supported
values for argument radix are
‘d’ for decimal, ‘o’ for octal, and
‘x’ for hexadecimal.
-
-
- --reverse-sort
- Reverse the order of the sort.
-
-
- --size-sort
- Sort symbols by size instead of alphabetically by
name.
-
-
- --undefined-only
- Display only undefined symbols.
-
-
- --version
- Display the version identifier for
nm and exit.
-
-
- -A
- Equivalent to specifying option
--print-file-name.
-
-
- -B
- Equivalent to specifying option
--format=bsd.
-
-
- -C
[style]
- Equivalent to specifying option
--demangle[=style].
-
-
- -D
- Equivalent to specifying option
--dynamic.
-
-
- -F
format
- Equivalent to specifying option
--format=format.
-
-
- -P
- Equivalent to specifying option
--format=posix.
-
-
- -S
- Equivalent to specifying option
--print-size.
-
-
- -V
- Equivalent to specifying option
--version.
-
-
- -a
- Equivalent to specifying option
--debug-syms.
-
-
- -e
- Only display information for global and static
symbols.
-
-
- -f
- Produce full output (default).
-
-
- -g
- Equivalent to specifying option
--extern-only.
-
-
- -h
- Equivalent to specifying option
--help.
-
-
- -l
- Equivalent to specifying option
--line-numbers.
-
-
- -n
- Equivalent to specifying option
--numeric-sort.
-
-
- -o
- If POSIX output was specified using the
-F posix or
-P options, this option is equivalent to
specifying
--radix=‘o’.
If POSIX output was not specified, this option acts as a synonym for the
--print-file-name option.
-
-
- -p
- Equivalent to specifying option
--no-sort.
-
-
- -v
- Equivalent to option -n.
-
-
- -r
- Equivalent to specifying option
--reverse-sort
-
-
- -s
- Equivalent to specifying option
--print-armap.
-
-
- -t
radix
- Equivalent to specifying option
--radix=radix.
-
-
- -u
- Equivalent to specifying option
--undefined-only.
-
-
- -x
- Write numeric values in hexadecimal (equivalent to -t
x).
The
nm utility can present its information in a
number of formats, numeric radices and sort orders. By default
nm uses BSD style output, a hexadecimal radix,
without output sorted alphabetically by name and without demangling of names.
For each symbol listed,
nm presents the following
information:
- The library or object name, if options
-A or
--print-file-name were specified.
- The symbol name.
- The type of the symbol denoted by a single character as
below:
- A
- A global, absolute symbol.
- B
- A global “bss” (uninitialized data)
symbol.
- C
- A “common” symbol, representing
uninitialized data.
- D
- A global symbol naming initialized data.
- N
- A debugger symbol.
- R
- A read-only data symbol.
- T
- A global text symbol.
- U
- An undefined symbol.
- V
- A weak object.
- W
- A weak reference.
- a
- A local absolute symbol.
- b
- A local “bss” (uninitialized data)
symbol.
- d
- A local data symbol.
- r
- A local read-only data symbol.
- t
- A local text symbol.
- v
- A weak object that is undefined.
- w
- A weak symbol that is undefined.
- ?
- None of the above.
- The value of the symbol.
- The size of the symbol if applicable.
- Line number information, if available and if options
-l or
--line-numbers were specified.
The
nm utility exits 0 on success,
and >0 if an error occurs.
ar(1),
objdump(1),
ranlib(1),
elf(3)
The
nm utility and this manual page were written by
Hyogeol Lee
<
hyogeollee@gmail.com>.