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

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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](#OPTIONS)

[-d destination\_dir](#d)

Put the resulting **.ph** files beneath **destination\_dir**, instead of beneath the default Perl library location ($Config{'installsitearch'}).

[-r](#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](#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](#l)

Symbolic links will be replicated in the destination directory. If **-l** is not specified, then links are skipped over.

[-h](#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](#e)

If an error is encountered during conversion, output file will be removed and a warning emitted instead of terminating the conversion immediately.

[-D](#D)

Include the code from the **.h** file as a comment in the **.ph** file. This is primarily used for debugging *h2ph*.

[-Q](#Q)

'Quiet' mode; don't print out the names of the files being converted.

# [ENVIRONMENT](#ENVIRONMENT)

No environment variables are used.

# [FILES](#FILES)

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

etc.

# [AUTHOR](#AUTHOR)

Larry Wall

# [SEE ALSO](#SEE_ALSO)

[**perl**(1)](/man/os/perl/perl.1)

# [DIAGNOSTICS](#DIAGNOSTICS)

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

# [BUGS](#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.

2026-10-27 perl v5.44.0

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Document: h2ph(1) from perl 5.44.0-r4 (Chainguard OS)
Source: https://github.com/Perl/perl5.git