Devel::PPPort - Perl/Pollution/Portability Devel::PPPort::WriteFile(); # defaults to ./ppport.h Devel::PPPort::WriteFile('someheader.h'); Perl's API has changed over time, gaining new features, new functions, increasing its flexibility, and reducing the impact on the C namespace environment (reduced pollution). The header file written by this module, typically ppport.h, attempts to bring some of the newer Perl API features to older versions of Perl, so that you can worry less about keeping track of old releases, but users can still reap the benefit. "Devel::PPPort" contains a single function, called "WriteFile". Its only purpose is to write the ppport.h C header file. This file contains a series of macros and, if explicitly requested, functions that allow XS modules to be built using older versions of Perl. Currently, Perl versions from 5.003 to 5.10.0 are supported. This module is used by "h2xs" to write the file ppport.h.

Why use ppport.h?
You should use ppport.h in modern code so that your code will work with the widest range of Perl interpreters possible, without significant additional work. You should attempt older code to fully use ppport.h, because the reduced pollution of newer Perl versions is an important thing. It's so important that the old polluting ways of original Perl modules will not be supported very far into the future, and your module will almost certainly break! By adapting to it now, you'll gain compatibility and a sense of having done the electronic ecology some good.

How to use ppport.h
Don't direct the users of your module to download "Devel::PPPort". They are most probably no XS writers. Also, don't make ppport.h optional. Rather, just take the most recent copy of ppport.h that you can find (e.g. by generating it with the latest "Devel::PPPort" release from CPAN), copy it into your project, adjust your project to use it, and distribute the header along with your module.

Running ppport.h
But ppport.h is more than just a C header. It's also a Perl script that can check your source code. It will suggest hints and portability notes, and can even make suggestions on how to change your code. You can run it like any other Perl program: perl ppport.h [options] [files] It also has embedded documentation, so you can use perldoc ppport.h to find out more about how to use it.

WriteFile
"WriteFile" takes one optional argument. When called with one argument, it expects to be passed a filename. When called with no arguments, it defaults to the filename ppport.h. The function returns a true value if the file was written successfully. Otherwise it returns a false value. ppport.h supports Perl versions from 5.003 to 5.10.0 in threaded and non-threaded configurations.

Provided Perl compatibility API
The header file written by this module, typically ppport.h, provides access to the following elements of the Perl API that is not available in older Perl releases: _aMY_CXT _pMY_CXT aMY_CXT aMY_CXT_ aTHX aTHX_ aTHXR aTHXR_ AvFILLp boolSV call_argv call_method call_pv call_sv ckWARN CopFILE CopFILE_set CopFILEAV CopFILEGV CopFILEGV_set CopFILESV CopSTASH CopSTASH_eq CopSTASH_set CopSTASHPV CopSTASHPV_set CopyD dAX dAXMARK DEFSV dITEMS dMY_CXT dMY_CXT_SV dNOOP dTHR dTHX dTHXa dTHXoa dTHXR dUNDERBAR dVAR dXCPT dXSTARG END_EXTERN_C ERRSV eval_pv eval_sv EXTERN_C get_av get_cv get_hv get_sv grok_bin grok_hex grok_number GROK_NUMERIC_RADIX grok_numeric_radix grok_oct gv_stashpvn hv_fetchs hv_stores IN_LOCALE IN_LOCALE_COMPILETIME IN_LOCALE_RUNTIME IN_PERL_COMPILETIME INT2PTR IS_NUMBER_GREATER_THAN_UV_MAX IS_NUMBER_IN_UV IS_NUMBER_INFINITY IS_NUMBER_NAN IS_NUMBER_NEG IS_NUMBER_NOT_INT IVdf IVSIZE IVTYPE load_module memEQ memNE MoveD mPUSHi mPUSHn mPUSHp mPUSHu mXPUSHi mXPUSHn mXPUSHp mXPUSHu MY_CXT MY_CXT_CLONE MY_CXT_INIT my_snprintf my_strlcat my_strlcpy newCONSTSUB newRV_inc newRV_noinc newSVpvn newSVpvn_share newSVpvs newSVuv Newx Newxc Newxz NOOP NUM2PTR NVef NVff NVgf NVTYPE packWARN PERL_ABS PERL_BCDVERSION PERL_GCC_BRACE_GROUPS_FORBIDDEN PERL_HASH PERL_INT_MAX PERL_INT_MIN PERL_LONG_MAX PERL_LONG_MIN PERL_MAGIC_arylen PERL_MAGIC_backref PERL_MAGIC_bm PERL_MAGIC_collxfrm PERL_MAGIC_dbfile PERL_MAGIC_dbline PERL_MAGIC_defelem PERL_MAGIC_env PERL_MAGIC_envelem PERL_MAGIC_ext PERL_MAGIC_fm PERL_MAGIC_glob PERL_MAGIC_isa PERL_MAGIC_isaelem PERL_MAGIC_mutex PERL_MAGIC_nkeys PERL_MAGIC_overload PERL_MAGIC_overload_elem PERL_MAGIC_overload_table PERL_MAGIC_pos PERL_MAGIC_qr PERL_MAGIC_regdata PERL_MAGIC_regdatum PERL_MAGIC_regex_global PERL_MAGIC_shared PERL_MAGIC_shared_scalar PERL_MAGIC_sig PERL_MAGIC_sigelem PERL_MAGIC_substr PERL_MAGIC_sv PERL_MAGIC_taint PERL_MAGIC_tied PERL_MAGIC_tiedelem PERL_MAGIC_tiedscalar PERL_MAGIC_utf8 PERL_MAGIC_uvar PERL_MAGIC_uvar_elem PERL_MAGIC_vec PERL_MAGIC_vstring PERL_QUAD_MAX PERL_QUAD_MIN PERL_REVISION PERL_SCAN_ALLOW_UNDERSCORES PERL_SCAN_DISALLOW_PREFIX PERL_SCAN_GREATER_THAN_UV_MAX PERL_SCAN_SILENT_ILLDIGIT PERL_SHORT_MAX PERL_SHORT_MIN PERL_SIGNALS_UNSAFE_FLAG PERL_SUBVERSION PERL_UCHAR_MAX PERL_UCHAR_MIN PERL_UINT_MAX PERL_UINT_MIN PERL_ULONG_MAX PERL_ULONG_MIN PERL_UNUSED_ARG PERL_UNUSED_CONTEXT PERL_UNUSED_DECL PERL_UNUSED_VAR PERL_UQUAD_MAX PERL_UQUAD_MIN PERL_USE_GCC_BRACE_GROUPS PERL_USHORT_MAX PERL_USHORT_MIN PERL_VERSION Perl_warner Perl_warner_nocontext PL_compiling PL_copline PL_curcop PL_curstash PL_DBsignal PL_DBsingle PL_DBsub PL_DBtrace PL_debstash PL_defgv PL_diehook PL_dirty PL_dowarn PL_errgv PL_expect PL_hexdigit PL_hints PL_laststatval PL_na PL_no_modify PL_perl_destruct_level PL_perldb PL_ppaddr PL_rsfp PL_rsfp_filters PL_signals PL_stack_base PL_stack_sp PL_statcache PL_stdingv PL_Sv PL_sv_arenaroot PL_sv_no PL_sv_undef PL_sv_yes PL_tainted PL_tainting pMY_CXT pMY_CXT_ Poison PoisonFree PoisonNew PoisonWith pTHX pTHX_ PTR2IV PTR2NV PTR2ul PTR2UV PTRV PUSHmortal PUSHu SAVE_DEFSV START_EXTERN_C START_MY_CXT STMT_END STMT_START STR_WITH_LEN sv_2pv_flags sv_2pv_nolen sv_2pvbyte sv_2pvbyte_nolen sv_2uv sv_catpv_mg sv_catpvf_mg sv_catpvf_mg_nocontext sv_catpvn_mg sv_catpvn_nomg sv_catpvs sv_catsv_mg sv_catsv_nomg SV_CONST_RETURN SV_COW_DROP_PV SV_COW_SHARED_HASH_KEYS SV_GMAGIC SV_HAS_TRAILING_NUL SV_IMMEDIATE_UNREF sv_magic_portable SV_MUTABLE_RETURN SV_NOSTEAL sv_pvn_force_flags sv_pvn_nomg sv_setiv_mg sv_setnv_mg sv_setpv_mg sv_setpvf_mg sv_setpvf_mg_nocontext sv_setpvn_mg sv_setpvs sv_setsv_mg sv_setsv_nomg sv_setuv sv_setuv_mg SV_SMAGIC sv_usepvn_mg SV_UTF8_NO_ENCODING sv_uv sv_vcatpvf sv_vcatpvf_mg sv_vsetpvf sv_vsetpvf_mg SVf SvGETMAGIC SvIV_nomg SvMAGIC_set SvPV_const SvPV_flags SvPV_flags_const SvPV_flags_const_nolen SvPV_flags_mutable SvPV_force SvPV_force_flags SvPV_force_flags_mutable SvPV_force_flags_nolen SvPV_force_mutable SvPV_force_nolen SvPV_force_nomg SvPV_force_nomg_nolen SvPV_mutable SvPV_nolen SvPV_nolen_const SvPV_nomg SvPV_nomg_const SvPV_nomg_const_nolen SvPVbyte SvPVX_const SvPVX_mutable SvREFCNT_inc SvREFCNT_inc_NN SvREFCNT_inc_simple SvREFCNT_inc_simple_NN SvREFCNT_inc_simple_void SvREFCNT_inc_simple_void_NN SvREFCNT_inc_void SvREFCNT_inc_void_NN SvRV_set SvSHARED_HASH SvSTASH_set SvUOK SvUV SvUV_nomg SvUV_set SvUVX SvUVx SvUVXx SvVSTRING_mg UNDERBAR UTF8_MAXBYTES UVof UVSIZE UVTYPE UVuf UVXf UVxf vload_module vnewSVpvf WARN_ALL WARN_AMBIGUOUS WARN_ASSERTIONS WARN_BAREWORD WARN_CLOSED WARN_CLOSURE WARN_DEBUGGING WARN_DEPRECATED WARN_DIGIT WARN_EXEC WARN_EXITING WARN_GLOB WARN_INPLACE WARN_INTERNAL WARN_IO WARN_LAYER WARN_MALLOC WARN_MISC WARN_NEWLINE WARN_NUMERIC WARN_ONCE WARN_OVERFLOW WARN_PACK WARN_PARENTHESIS WARN_PIPE WARN_PORTABLE WARN_PRECEDENCE WARN_PRINTF WARN_PROTOTYPE WARN_QW WARN_RECURSION WARN_REDEFINE WARN_REGEXP WARN_RESERVED WARN_SEMICOLON WARN_SEVERE WARN_SIGNAL WARN_SUBSTR WARN_SYNTAX WARN_TAINT WARN_THREADS WARN_UNINITIALIZED WARN_UNOPENED WARN_UNPACK WARN_UNTIE WARN_UTF8 WARN_VOID warner XCPT_CATCH XCPT_RETHROW XCPT_TRY_END XCPT_TRY_START XPUSHmortal XPUSHu XSprePUSH XSRETURN XSRETURN_UV XST_mUV ZeroD

Perl API not supported by ppport.h
There is still a big part of the API not supported by ppport.h. Either because it doesn't make sense to back-port that part of the API, or simply because it hasn't been implemented yet. Patches welcome! Here's a list of the currently unsupported API, and also the version of Perl below which it is unsupported: MULTICALL POP_MULTICALL PUSH_MULTICALL Perl_signbit SvRX SvRXOK av_create_and_push av_create_and_unshift_one get_cvn_flags gv_fetchfile_flags hv_assert mro_get_linear_isa mro_get_linear_isa_c3 mro_get_linear_isa_dfs mro_method_changed_in my_dirfd newSV_type pad_sv pregcomp ptr_table_clear ptr_table_fetch ptr_table_free ptr_table_new ptr_table_split ptr_table_store re_compile re_intuit_start reg_named_buff_all reg_named_buff_exists reg_named_buff_fetch reg_named_buff_firstkey reg_named_buff_nextkey reg_named_buff_scalar reg_stringify regfree_internal savesharedpvn scan_vstring stashpv_hvname_match upg_version PerlIO_context_layers gv_name_set my_vsnprintf newXS_flags pv_escape pv_pretty regclass_swash sv_does sv_usepvn_flags av_arylen_p ckwarn ckwarn_d csighandler dMULTICALL doref gv_const_sv gv_stashpvs hv_eiter_p hv_eiter_set hv_name_set hv_placeholders_get hv_placeholders_p hv_placeholders_set hv_riter_p hv_riter_set is_utf8_string_loclen my_sprintf newGIVENOP newSVhek newSVpvs_share newWHENOP newWHILEOP ref savepvs sortsv_flags vverify SvPVbyte_force find_rundefsvoffset gv_fetchpvn_flags gv_fetchsv op_refcnt_lock op_refcnt_unlock savesvpv vnormal hv_clear_placeholders hv_scalar scan_version sv_2iv_flags sv_2uv_flags new_version save_set_svflags vcmp vnumify vstringify SvIsCOW SvIsCOW_shared_hash SvVOK doing_taint find_runcv is_utf8_string_loc packlist save_bool savestack_grow_cnt seed sv_cat_decode sv_compile_2op sv_setpviv sv_setpviv_mg unpackstring hv_iternext_flags hv_store_flags is_utf8_idcont nothreadhook PerlIO_clearerr PerlIO_close PerlIO_eof PerlIO_error PerlIO_fileno PerlIO_fill PerlIO_flush PerlIO_get_base PerlIO_get_bufsiz PerlIO_get_cnt PerlIO_get_ptr PerlIO_read PerlIO_seek PerlIO_set_cnt PerlIO_set_ptrcnt PerlIO_setlinebuf PerlIO_stderr PerlIO_stdin PerlIO_stdout PerlIO_tell PerlIO_unread PerlIO_write SvLOCK SvSHARE SvUNLOCK atfork_lock atfork_unlock custom_op_desc custom_op_name deb debstack debstackptrs gv_fetchmeth_autoload ibcmp_utf8 my_fork my_socketpair pack_cat perl_destruct pv_uni_display save_shared_pvref savesharedpv sortsv sv_copypv sv_magicext sv_nolocking sv_nosharing sv_recode_to_utf8 sv_uni_display to_uni_fold to_uni_lower to_uni_title to_uni_upper to_utf8_case to_utf8_fold to_utf8_lower to_utf8_title to_utf8_upper unpack_str uvchr_to_utf8_flags uvuni_to_utf8_flags vdeb calloc getcwd_sv init_tm malloc mfree mini_mktime my_atof2 my_strftime op_null realloc sv_catpvn_flags sv_catsv_flags sv_setsv_flags sv_utf8_upgrade_flags swash_fetch POPpbytex bytes_from_utf8 despatch_signals do_openn gv_handler is_lvalue_sub my_popen_list save_mortalizesv save_padsv scan_num sv_force_normal_flags sv_setref_uv sv_unref_flags sv_utf8_upgrade utf8_length utf8_to_uvchr utf8_to_uvuni utf8n_to_uvuni uvuni_to_utf8 SvGAMAGIC apply_attrs_string bytes_to_utf8 gv_efullname4 gv_fullname4 is_utf8_string save_generic_pvref utf16_to_utf8 utf16_to_utf8_reversed utf8_to_bytes SvIOK_UV SvIOK_notUV SvIOK_only_UV SvPOK_only_UTF8 SvPVbyte_nolen SvPVbytex SvPVbytex_force SvPVutf8 SvPVutf8_force SvPVutf8_nolen SvPVutf8x SvPVutf8x_force SvUOK SvUTF8 SvUTF8_off SvUTF8_on av_delete av_exists call_atexit cast_i32 cast_iv cast_ulong cast_uv do_gv_dump do_gvgv_dump do_hv_dump do_magic_dump do_op_dump do_open9 do_pmop_dump do_sv_dump dump_all dump_eval dump_form dump_indent dump_packsubs dump_sub dump_vindent get_context get_ppaddr gv_dump init_i18nl10n init_i18nl14n is_uni_alnum is_uni_alnum_lc is_uni_alnumc is_uni_alnumc_lc is_uni_alpha is_uni_alpha_lc is_uni_ascii is_uni_ascii_lc is_uni_cntrl is_uni_cntrl_lc is_uni_digit is_uni_digit_lc is_uni_graph is_uni_graph_lc is_uni_idfirst is_uni_idfirst_lc is_uni_lower is_uni_lower_lc is_uni_print is_uni_print_lc is_uni_punct is_uni_punct_lc is_uni_space is_uni_space_lc is_uni_upper is_uni_upper_lc is_uni_xdigit is_uni_xdigit_lc is_utf8_alnum is_utf8_alnumc is_utf8_alpha is_utf8_ascii is_utf8_char is_utf8_cntrl is_utf8_digit is_utf8_graph is_utf8_idfirst is_utf8_lower is_utf8_mark is_utf8_print is_utf8_punct is_utf8_space is_utf8_upper is_utf8_xdigit magic_dump mess my_atof my_fflush_all newANONATTRSUB newATTRSUB newXS newXSproto new_collate new_ctype new_numeric op_dump perl_parse pmop_dump pv_display re_intuit_string reginitcolors require_pv safesyscalloc safesysfree safesysmalloc safesysrealloc save_I8 save_alloc save_destructor save_destructor_x save_re_context save_vptr scan_bin set_context set_numeric_local set_numeric_radix set_numeric_standard str_to_version sv_2pvutf8 sv_2pvutf8_nolen sv_force_normal sv_len_utf8 sv_pos_b2u sv_pos_u2b sv_pv sv_pvbyte sv_pvbyten sv_pvbyten_force sv_pvutf8 sv_pvutf8n sv_pvutf8n_force sv_rvweaken sv_utf8_decode sv_utf8_downgrade sv_utf8_encode swash_init tmps_grow to_uni_lower_lc to_uni_title_lc to_uni_upper_lc utf8_distance utf8_hop vcroak vform vmess vwarn vwarner POPpx get_vtbl save_generic_svref PL_modglobal cx_dump debop debprofdump fbm_compile fbm_instr get_op_descs get_op_names init_stacks mg_length mg_size newHVhv new_stackinfo regdump regexec_flags regnext runops_debug runops_standard save_hints save_iv screaminstr sv_iv sv_nv sv_peek sv_true do_binmode save_aelem save_helem GIMME_V G_VOID HEf_SVKEY HeHASH HeKEY HeKLEN HePV HeSVKEY HeSVKEY_force HeSVKEY_set HeVAL SvSetMagicSV SvSetMagicSV_nosteal SvSetSV_nosteal SvTAINTED SvTAINTED_off SvTAINTED_on block_gimme call_list cv_const_sv delimcpy do_open form gv_autoload4 gv_efullname3 gv_fetchmethod_autoload gv_fullname3 hv_delayfree_ent hv_delete_ent hv_exists_ent hv_fetch_ent hv_free_ent hv_iterkeysv hv_ksplit hv_store_ent ibcmp_locale my_failure_exit my_memcmp my_pclose my_popen newSVpvf rsignal rsignal_state save_I16 save_gp share_hek start_subparse sv_catpvf sv_catpvf_mg sv_cmp_locale sv_derived_from sv_gets sv_magic_portable sv_setpvf sv_setpvf_mg sv_taint sv_tainted sv_untaint sv_vcatpvf sv_vcatpvf_mg sv_vcatpvfn sv_vsetpvf sv_vsetpvf_mg sv_vsetpvfn unsharepvn vnewSVpvf warner If you find any bugs, "Devel::PPPort" doesn't seem to build on your system or any of its tests fail, please use the CPAN Request Tracker at <http://rt.cpan.org/> to create a ticket for the module. Version 1.x of Devel::PPPort was written by Kenneth Albanowski. Version 2.x was ported to the Perl core by Paul Marquess. Version 3.x was ported back to CPAN by Marcus Holland-Moritz. Version 3.x, Copyright (C) 2004-2007, Marcus Holland-Moritz. Version 2.x, Copyright (C) 2001, Paul Marquess. Version 1.x, Copyright (C) 1999, Kenneth Albanowski. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See h2xs, ppport.h.