c++filt - GNU Binary Utilities

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## 9 c++filt

         c++filt [-_|--strip-underscores]
                 [-j|--java]
                 [-n|--no-strip-underscores]
                 [-p|--no-params]
                 [-s format|--format=format]
                 [--help]  [--version]  [symbol...]

The C++ and Java languages provides function overloading, which means that you can write many functions with the same name (providing each takes parameters of different types). All C++ and Java function names are encoded into a low-level assembly label (this process is known as mangling). The c++filt 1 program does the inverse mapping: it decodes (demangles) low-level names into user-level names so that the linker can keep these overloaded functions from clashing.

Every alphanumeric word (consisting of letters, digits, underscores, dollars, or periods) seen in the input is a potential label. If the label decodes into a C++ name, the C++ name replaces the low-level name in the output.

You can use c++filt to decipher individual symbols:

         c++filt symbol

If no symbol arguments are given, c++filt reads symbol names from the standard input and writes the demangled names to the standard output. All results are printed on the standard output.

-_
--strip-underscores
  On some systems, both the C and C++ compilers put an underscore in front of every name. For example, the C name `foo` gets the low-level name `_foo`. This option removes the initial underscore. Whether c++filt removes the underscore by default is target dependent.
-j
--java
  Prints demangled names using Java syntax. The default is to use C++ syntax.
-n
--no-strip-underscores
  Do not remove the initial underscore.
-p
--no-params
  When demangling the name of a function, do not display the types of the function's parameters.
-s format
--format=format
  c++filt can decode various methods of mangling, used by different compilers. The argument to this option selects which method it uses:
  `auto`
    Automatic selection based on executable (the default method)
  `gnu`
    the one used by the gnu C++ compiler (g++)
  `lucid`
    the one used by the Lucid compiler (lcc)
  `arm`
    the one specified by the C++ Annotated Reference Manual
  `hp`
    the one used by the HP compiler (aCC)
  `edg`
    the one used by the EDG compiler
  `gnu-v3`
    the one used by the gnu C++ compiler (g++) with the V3 ABI.
  `java`
    the one used by the gnu Java compiler (gcj)
  `gnat`
    the one used by the gnu Ada compiler (GNAT).
--help
  Print a summary of the options to c++filt and exit.
--version
  Print the version number of c++filt and exit.

> Warning: c++filt is a new utility, and the details of its user interface are subject to change in future releases. In particular, a command-line option may be required in the the future to decode a name passed as an argument on the command line; in other words,

>               c++filt symbol

> may in a future release become

>               c++filt option symbol

#### Footnotes

[1] MS-DOS does not allow `+` characters in file names, so on MS-DOS this program is named CXXFILT.