2 nm

     
     nm [
        -A
      
|
        -o
      
|
        --print-file-name
      
] [
        -a
      
|
        --debug-syms
      
]
        [
        -B
      
|
        --format=bsd
      
] [
        -C
      
|
        --demangle
      
[=style
]]
        [
        -D
      
|
        --dynamic
      
] [
        -f
      
      format
|
        --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
      
] [
        --with-symbol-versions
      
] [
        --target=
      
      bfdname
]
        [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 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. See c++filt , for more information on demangling.
--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. For ELF objects symbol sizes are read from the ELF, for other object types the symbol sizes are 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 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.
--with-symbol-versions
Enables the display of symbol version information if any exists. The version string is displayed as a suffix to the symbol name, preceeded by an @ character. For example ‘ foo@VER_1 ’. If the version is the default version to be used when resolving unversioned references to the symbol then it is displayed as a suffix preceeded by two @ characters. For example ‘ foo@@VER_2 ’.
--target= bfdname
Specify an object code format other than your system's default format. See Target Selection , for more information.