H2PH(1) | Perl Programmers Reference Guide | H2PH(1)

# NAME

h2ph - convert .h C header files to .ph Perl header files

# SYNOPSIS

h2ph [-d destination directory] [-r | -a] [-l] [-h] [-e] [-D] [-Q] [headerfiles]

# DESCRIPTION

h2ph converts any C header files specified to the corresponding Perl header file format. It is most easily run while in /usr/include:

            cd /usr/include; h2ph * sys/*

or

            cd /usr/include; h2ph * sys/* arpa/* netinet/*

or

            cd /usr/include; h2ph -r -l .

The output files are placed in the hierarchy rooted at Perl's architecture dependent library directory. You can specify a different hierarchy with a -d switch.

If run with no arguments, filters standard input to standard output.

# OPTIONS

-d destination_dir
  Put the resulting .ph files beneath destination_dir, instead of beneath the default Perl library location ($Config{'installsitearch'}).
-r
  Run recursively; if any of headerfiles are directories, then run h2ph on all files in those directories (and their subdirectories, etc.). -r and -a are mutually exclusive.
-a
  Run automagically; convert headerfiles, as well as any .h files which they include. This option will search for .h files in all directories which your C compiler ordinarily uses. -a and -r are mutually exclusive.
-l
  Symbolic links will be replicated in the destination directory. If -l is not specified, then links are skipped over.
-h
  Put 'hints' in the .ph files which will help in locating problems with h2ph. In those cases when you require a .ph file containing syntax errors, instead of the cryptic

              [ some error condition ] at (eval mmm) line nnn

  you will see the slightly more helpful

              [ some error condition ] at filename.ph line nnn

  However, the .ph files almost double in size when built using -h.

-e
  If an error is encountered during conversion, output file will be removed and a warning emitted instead of terminating the conversion immediately.
-D
  Include the code from the .h file as a comment in the .ph file. This is primarily used for debugging h2ph.
-Q
  'Quiet' mode; don't print out the names of the files being converted.

# ENVIRONMENT

No environment variables are used.

# FILES

     /usr/include/*.h
     /usr/include/sys/*.h

etc.

# AUTHOR

Larry Wall

# SEE ALSO

perl(1)

# DIAGNOSTICS

The usual warnings if it can't read or write the files involved.

# BUGS

Doesn't construct the %sizeof array for you.

It doesn't handle all C constructs, but it does attempt to isolate definitions inside evals so that you can get at the definitions that it can translate.

It's only intended as a rough tool. You may need to dicker with the files produced.

You have to run this program by hand; it's not run as part of the Perl installation.

Doesn't handle complicated expressions built piecemeal, a la:

        enum {
            FIRST_VALUE,
            SECOND_VALUE,
        #ifdef ABC
            THIRD_VALUE
        #endif
        };

Doesn't necessarily locate all of your C compiler's internally-defined symbols.

2025-10-12 | perl v5.40.1