c2hs1

Usage

Overview

This manual page briefly describes the c2hs command. For more details, refer to the main documentation, which is available in various other formats, including SGML and HTML; see below.

Options

The programs follow the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of options are included below. For a complete description, see the other documentation.

c2hs accepts the following options:

-h, -?, --help

brief help

-v, --version

show version information

--numeric-version

show version number

-c CPP, --cpp=CPP

use executable CPP to invoke C preprocessor

-C CPPOPTS, --cppopts=CPPOPTS

pass CPPOPTS to the C preprocessor

-p PLATFORM, --platform=PLATFORM

platform to use for cross compilation

-k, --keep

keep pre-processed C header

-l, --copy-library

copy `C2HS' library module to the current directory

-d TYPE, --dump=TYPE

dump internal information (for debugging), where TYPE is one of:

• trace

trace compiler phases

• genbind

trace binding generation

• ctrav

trace C declaration traversal

• chs

dump the binding file (adds .dump to the name)

header-file is the header file belonging to the marshalled library. It must end with suffix .h.

binding-file is the corresponding Haskell binding file, which must end with suffix .chs.

PLATFORM The platform name can be one of: x86_64-linux. i686-linux. m68k-palmos. This allows for cross-compilation, assuming the rest of your toolchain supports that. The default is the current host platform.

The most useful of these options is probably --cppopts (or -C). If the C header file needs any special options (like -D or -I) to go through the C pre-processor, here is the place to pass them.

Examples

The easiest way to use the C->Haskell Interface Generator is via Cabal. Cabal knows about .chs files and will run c2hs automatically, passing the appropriate flags.

When used directly, c2hs is usually called as:

c2hs lib.h Lib.chs

where lib.h is the header file and Lib.chs the Haskell binding module, which define the C- and Haskell-side interface, respectively. If no errors occur, the result is a pure Haskell module Lib.hs, which implements the Haskell API of the library.

A more advanced call may look like this:

c2hs --cppopts=-I/some/obscure/dir --cppopts=-DEXTRA lib.h Lib.chs

Often, lib.h will not be in the current directory, but in one of the header file directories. Apart from the current directory, C->Haskell looks in two places for the header: first, in the standard include directory of the used system, this is usually /usr/include and /usr/local/include; and second, it will look in every directory that is mentioned in a -IDIR option passed to the pre-processor via --cppopts.

Caveats

If you have more than one option that you want to give to the pre-processor, use multiple --cppopts= flags.