## 12 windres

`windres` may be used to manipulate Windows resources.

> Warning: `windres` is not always built as part of the binary utilities, since it is only useful for Windows targets.

    windres [options] [input-file] [output-file]

`windres` reads resources from an input file and copies them into an output file. Either file may be in one of three formats:

`rc`

  A text format read by the Resource Compiler.

`res`

  A binary format generated by the Resource Compiler.

`coff`

  A COFF object or executable.

The exact description of these different formats is available in documentation from Microsoft.

When `windres` converts from the `rc` format to the `res` format, it is acting like the Windows Resource Compiler. When `windres` converts from the `res` format to the `coff` format, it is acting like the Windows `CVTRES` program.

When `windres` generates an `rc` file, the output is similar but not identical to the format expected for the input. When an input `rc` file refers to an external filename, an output `rc` file will instead include the file contents.

If the input or output format is not specified, `windres` will guess based on the file name, or, for the input file, the file contents. A file with an extension of `.rc` will be treated as an `rc` file, a file with an extension of `.res` will be treated as a `res` file, and a file with an extension of `.o` or `.exe` will be treated as a `coff` file.

If no output file is specified, `windres` will print the resources in `rc` format to standard output.

The normal use is for you to write an `rc` file, use `windres` to convert it to a COFF object file, and then link the COFF file into your application. This will make the resources described in the `rc` file available to Windows.

`-i filename`
`--input filename`

  The name of the input file. If this option is not used, then `windres` will use the first non-option argument as the input file name. If there are no non-option arguments, then `windres` will read from standard input. `windres` can not read a COFF file from standard input.

`-o filename`
`--output filename`

  The name of the output file. If this option is not used, then `windres` will use the first non-option argument, after any used for the input file name, as the output file name. If there is no non-option argument, then `windres` will write to standard output. `windres` can not write a COFF file to standard output. Note, for compatibility with `rc` the option `-fo` is also accepted, but its use is not recommended.

`-J format`
`--input-format format`

  The input format to read. format may be ‘`res`’, ‘`rc`’, or ‘`coff`’. If no input format is specified, `windres` will guess, as described above.

`-O format`
`--output-format format`

  The output format to generate. format may be ‘`res`’, ‘`rc`’, or ‘`coff`’. If no output format is specified, `windres` will guess, as described above.

`-F target`
`--target target`

  Specify the BFD format to use for a COFF file as input or output. This is a BFD target name; you can use the `--help` option to see a list of supported targets. Normally `windres` will use the default format, which is the first one listed by the `--help` option. Target Selection.

`--preprocessor program`

  When `windres` reads an `rc` file, it runs it through the C preprocessor first. This option may be used to specify the preprocessor to use, including any leading arguments. The default preprocessor argument is `gcc -E -xc-header -DRC_INVOKED`.

`--preprocessor-arg option`

  When `windres` reads an `rc` file, it runs it through the C preprocessor first. This option may be used to specify additional text to be passed to preprocessor on its command line. This option can be used multiple times to add multiple options to the preprocessor command line.

`-I directory`
`--include-dir directory`

  Specify an include directory to use when reading an `rc` file. `windres` will pass this to the preprocessor as an `-I` option. `windres` will also search this directory when looking for files named in the `rc` file. If the argument passed to this command matches any of the supported formats (as described in the `-J` option), it will issue a deprecation warning, and behave just like the `-J` option. New programs should not use this behaviour. If a directory happens to match a format, simple prefix it with ‘`./`’ to disable the backward compatibility.

`-D target`
`--define sym[=val]`

  Specify a `-D` option to pass to the preprocessor when reading an `rc` file.

`-U target`
`--undefine sym`

  Specify a `-U` option to pass to the preprocessor when reading an `rc` file.

`-r`

  Ignored for compatibility with rc.

`-v`

  Enable verbose mode. This tells you what the preprocessor is if you didn’t specify one.

`-c val`
`--codepage val`

  Specify the default codepage to use when reading an `rc` file. val should be a hexadecimal prefixed by ‘`0x`’ or decimal codepage code. The valid range is from zero up to 0xffff, but the validity of the codepage is host and configuration dependent.

`-l val`
`--language val`

  Specify the default language to use when reading an `rc` file. val should be a hexadecimal language code. The low eight bits are the language, and the high eight bits are the sublanguage.

`--use-temp-file`

  Use a temporary file to instead of using popen to read the output of the preprocessor. Use this option if the popen implementation is buggy on the host (eg., certain non-English language versions of Windows 95 and Windows 98 are known to have buggy popen where the output will instead go the console).

`--no-use-temp-file`

  Use popen, not a temporary file, to read the output of the preprocessor. This is the default behaviour.

`-h`
`--help`

  Prints a usage summary.

`-V`
`--version`

  Prints the version number for `windres`.

`--yydebug`

  If `windres` is compiled with `YYDEBUG` defined as `1`, this will turn on parser debugging.