NAME

perlos2 - Perl under OS/2, DOS, Win0.3*, Win0.95 and WinNT.


SYNOPSIS

One can read this document in the following formats:

        man perlos2
        view perl perlos2
        explorer perlos2.html
        info perlos2

to list some (not all may be available simultaneously), or it may be read as is: either as README.os2, or pod/perlos2.pod.

To read the .INF version of documentation (very recommended) outside of OS/2, one needs an IBM's reader (may be available on IBM ftp sites (?) (URL anyone?)) or shipped with PC DOS 7.0 and IBM's Visual Age C++ 3.5.

A copy of a Win* viewer is contained in the ``Just add OS/2 Warp'' package

  ftp://ftp.software.ibm.com/ps/products/os2/tools/jaow/jaow.zip

in ?:\JUST_ADD\view.exe. This gives one an access to EMX's .INF docs as well (text form is available in /emx/doc in EMX's distribution).

Note that if you have lynx.exe installed, you can follow WWW links from this document in .INF format. If you have EMX docs installed correctly, you can follow library links (you need to have view emxbook working by setting EMXBOOK environment variable as it is described in EMX docs).


Target

The target is to make OS/2 the best supported platform for using/building/developing Perl and Perl applications, as well as make Perl the best language to use under OS/2. The secondary target is to try to make this work under DOS and Win* as well (but not too hard).

The current state is quite close to this target. Known limitations:

Please keep this list up-to-date by informing me about other items.


Other OSes

Since OS/2 port of perl uses a remarkable EMX environment, it can run (and build extensions, and - possibly - be build itself) under any environment which can run EMX. The current list is DOS, DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT. Out of many perl flavors, only one works, see perl_.exe.

Note that not all features of Perl are available under these environments. This depends on the features the extender - most probably RSX - decided to implement.

Cf. Prerequisites.


Prerequisites

EMX

EMX runtime is required (may be substituted by RSX). Note that it is possible to make perl_.exe to run under DOS without any external support by binding emx.exe/rsx.exe to it, see emxbind. Note that under DOS for best results one should use RSX runtime, which has much more functions working (like fork, popen and so on). In fact RSX is required if there is no VCPI present. Note the RSX requires DPMI.

Only the latest runtime is supported, currently 0.9c. Perl may run under earlier versions of EMX, but this is not tested.

One can get different parts of EMX from, say

  ftp://ftp.cdrom.com/pub/os2/emx09c/
  ftp://hobbes.nmsu.edu/os2/unix/emx09c/

The runtime component should have the name emxrt.zip.

NOTE. It is enough to have emx.exe/rsx.exe on your path. One does not need to specify them explicitly (though this

  emx perl_.exe -de 0

will work as well.)

RSX

To run Perl on DPMI platforms one needs RSX runtime. This is needed under DOS-inside-OS/2, Win0.3*, Win0.95 and WinNT (see Other OSes). RSX would not work with VCPI only, as EMX would, it requires DMPI.

Having RSX and the latest sh.exe one gets a fully functional *nix-ish environment under DOS, say, fork, `` and pipe-open work. In fact, MakeMaker works (for static build), so one can have Perl development environment under DOS.

One can get RSX from, say

  ftp://ftp.cdrom.com/pub/os2/emx09c/contrib
  ftp://ftp.uni-bielefeld.de/pub/systems/msdos/misc
  ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/contrib

Contact the author on rainer@mathematik.uni-bielefeld.de.

The latest sh.exe with DOS hooks is available at

  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip
HPFS

Perl does not care about file systems, but to install the whole perl library intact one needs a file system which supports long file names.

Note that if you do not plan to build the perl itself, it may be possible to fool EMX to truncate file names. This is not supported, read EMX docs to see how to do it.

pdksh

To start external programs with complicated command lines (like with pipes in between, and/or quoting of arguments), Perl uses an external shell. With EMX port such shell should be named < sh.exe>, and located either in the wired-in-during-compile locations (usually F:/bin), or in configurable location (see PERL_SH_DIR).

For best results use EMX pdksh. The soon-to-be-available standard binary (5.2.12?) runs under DOS (with RSX) as well, meanwhile use the binary from

  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/sh_dos.zip


Starting Perl programs under OS/2 (and DOS and...)

Start your Perl program foo.pl with arguments arg1 arg2 arg3 the same way as on any other platform, by

        perl foo.pl arg1 arg2 arg3

If you want to specify perl options -my_opts to the perl itself (as opposed to to your program), use

        perl -my_opts foo.pl arg1 arg2 arg3

Alternately, if you use OS/2-ish shell, like CMD or 4os2, put the following at the start of your perl script:

        extproc perl -S -my_opts

rename your program to foo.cmd, and start it by typing

        foo arg1 arg2 arg3

Note that because of stupid OS/2 limitations the full path of the perl script is not available when you use extproc, thus you are forced to use -S perl switch, and your script should be on path. As a plus side, if you know a full path to your script, you may still start it with

        perl ../../blah/foo.cmd arg1 arg2 arg3

(note that the argument -my_opts is taken care of by the extproc line in your script, see extproc on the first line).

To understand what the above magic does, read perl docs about -S switch - see the perlrun manpage, and cmdref about extproc:

        view perl perlrun
        man perlrun
        view cmdref extproc
        help extproc

or whatever method you prefer.

There are also endless possibilities to use executable extensions of 4os2, associations of WPS and so on... However, if you use *nixish shell (like sh.exe supplied in the binary distribution), you need to follow the syntax specified in Switches.

Note that -S switch enables a search with additional extensions .cmd, .btm, .bat, .pl as well.


Starting OS/2 (and DOS) programs under Perl

This is what system() (see system), `` (see I/O Operators), and open pipe (see open) are for. (Avoid exec() (see exec) unless you know what you do).

Note however that to use some of these operators you need to have a sh-syntax shell installed (see Pdksh, Frequently asked questions), and perl should be able to find it (see PERL_SH_DIR).

The cases when the shell is used are:

  1. One-argument system() (see system), exec() (see exec) with redirection or shell meta-characters;

  2. Pipe-open (see open) with the command which contains redirection or shell meta-characters;

  3. Backticks `` (see I/O Operators) with the command which contains redirection or shell meta-characters;

  4. If the executable called by system()/exec()/pipe-open()/ `` is a script with the ``magic'' #! line or extproc line which specifies shell;

  5. If the executable called by system()/exec()/pipe-open()/ `` is a script without ``magic'' line, and $ENV{EXECSHELL} is set to shell;

  6. If the executable called by system()/exec()/pipe-open()/ `` is not found;

  7. For globbing (see glob, I/O Operators).

For the sake of speed for a common case, in the above algorithms backslashes in the command name are not considered as shell metacharacters.

Perl starts scripts which begin with cookies extproc or #! directly, without an intervention of shell. Perl uses the same algorithm to find the executable as pdksh: if the path on #! line does not work, and contains /, then the executable is searched in . and on PATH. To find arguments for these scripts Perl uses a different algorithm than pdksh: up to 3 arguments are recognized, and trailing whitespace is stripped.

If a script does not contain such a cooky, then to avoid calling sh.exe, Perl uses the same algorithm as pdksh: if $ENV{EXECSHELL} is set, the script is given as the first argument to this command, if not set, then $ENV{COMSPEC} /c is used (or a hardwired guess if $ENV{COMSPEC} is not set).

If starting scripts directly, Perl will use exactly the same algorithm as for the search of script given by -S command-line option: it will look in the current directory, then on components of $ENV{PATH} using the following order of appended extensions: no extension, .cmd, .btm, .bat, .pl.

Note that Perl will start to look for scripts only if OS/2 cannot start the specified application, thus system 'blah' will not look for a script if there is an executable file blah.exe anywhere on PATH.

Note also that executable files on OS/2 can have an arbitrary extension, but .exe will be automatically appended if no dot is present in the name. The workaround as as simple as that: since blah. and blah denote the same file, to start an executable residing in file n:/bin/blah (no extension) give an argument n:/bin/blah. to system().

The last note is that currently it is not straightforward to start PM programs from VIO (=text-mode) Perl process and visa versa. Either ensure that shell will be used, as in system 'cmd /c epm', or start it using optional arguments to system() documented in OS2::Process module. This is considered a bug and should be fixed soon.


Frequently asked questions


I cannot run external programs

Did you run your programs with -w switch? See Starting OS.

Do you try to run internal shell commands, like `copy a b` (internal for cmd.exe), or `glob a*b` (internal for ksh)? You need to specify your shell explicitly, like `cmd /c copy a b`, since Perl cannot deduce which commands are internal to your shell.


I cannot embed perl into my program, or use perl.dll from my program.

Is your program EMX-compiled with -Zmt -Zcrtdll?

If not, you need to build a stand-alone DLL for perl. Contact me, I did it once. Sockets would not work, as a lot of other stuff.

Did you use ExtUtils::Embed?

I had reports it does not work. Somebody would need to fix it.


`` and pipe-open do not work under DOS.

This may a variant of just I cannot run external programs, or a deeper problem. Basically: you need RSX (see Prerequisites) for these commands to work, and you may need a port of sh.exe which understands command arguments. One of such ports is listed in Prerequisites under RSX. Do not forget to set variable <A HREF="#PERL_SH_DIR">PERL_SH_DIR</A> as well.

DPMI is required for RSX.


Cannot start find.exe "pattern" file

Use one of

  system 'cmd', '/c', 'find "pattern" file';
  `cmd /c 'find "pattern" file'`

This would start find.exe via cmd.exe via sh.exe via perl.exe, but this is a price to pay if you want to use non-conforming program. In fact find.exe cannot be started at all using C library API only. Otherwise the following command-lines were equivalent:

  find "pattern" file
  find pattern file


INSTALLATION


Automatic binary installation

The most convenient way of installing perl is via perl installer install.exe. Just follow the instructions, and 99% of the installation blues would go away.

Note however, that you need to have unzip.exe on your path, and EMX environment running. The latter means that if you just installed EMX, and made all the needed changes to Config.sys, you may need to reboot in between. Check EMX runtime by running

        emxrev

A folder is created on your desktop which contains some useful objects.

Things not taken care of by automatic binary installation:

PERL_BADLANG

may be needed if you change your codepage after perl installation, and the new value is not supported by EMX. See PERL_BADLANG.

PERL_BADFREE

see PERL_BADFREE.

Config.pm

This file resides somewhere deep in the location you installed your perl library, find it out by

  perl -MConfig -le "print $INC{'Config.pm'}"

While most important values in this file are updated by the binary installer, some of them may need to be hand-edited. I know no such data, please keep me informed if you find one.

NOTE. Because of a typo the binary installer of 5.00305 would install a variable PERL_SHPATH into Config.sys. Please remove this variable and put <EM>PERL_SH_DIR</EM> instead.


Manual binary installation

As of version 5.00305, OS/2 perl binary distribution comes split into 11 components. Unfortunately, to enable configurable binary installation, the file paths in the zip files are not absolute, but relative to some directory.

Note that the extraction with the stored paths is still necessary (default with unzip, specify -d to pkunzip). However, you need to know where to extract the files. You need also to manually change entries in Config.sys to reflect where did you put the files. Note that if you have some primitive unzipper (like pkunzip), you may get a lot of warnings/errors during unzipping. Upgrade to (w)unzip.

Below is the sample of what to do to reproduce the configuration on my machine:

Perl VIO and PM executables (dynamically linked)

  unzip perl_exc.zip *.exe *.ico -d f:/emx.add/bin
  unzip perl_exc.zip *.dll -d f:/emx.add/dll

(have the directories with *.exe on PATH, and *.dll on LIBPATH);

Perl_ VIO executable (statically linked)

  unzip perl_aou.zip -d f:/emx.add/bin

(have the directory on PATH);

Executables for Perl utilities

  unzip perl_utl.zip -d f:/emx.add/bin

(have the directory on PATH);

Main Perl library

  unzip perl_mlb.zip -d f:/perllib/lib

If this directory is preserved, you do not need to change anything. However, for perl to find it if it is changed, you need to set PERLLIB_PREFIX in Config.sys, see PERLLIB_PREFIX.

Additional Perl modules

  unzip perl_ste.zip -d f:/perllib/lib/site_perl

If you do not change this directory, do nothing. Otherwise put this directory and subdirectory ./os2 in PERLLIB or PERL5LIB variable. Do not use PERL5LIB unless you have it set already. See ENVIRONMENT.

Tools to compile Perl modules

  unzip perl_blb.zip -d f:/perllib/lib

If this directory is preserved, you do not need to change anything. However, for perl to find it if it is changed, you need to set PERLLIB_PREFIX in Config.sys, see PERLLIB_PREFIX.

Manpages for Perl and utilities

  unzip perl_man.zip -d f:/perllib/man

This directory should better be on MANPATH. You need to have a working man to access these files.

Manpages for Perl modules

  unzip perl_mam.zip -d f:/perllib/man

This directory should better be on MANPATH. You need to have a working man to access these files.

Source for Perl documentation

  unzip perl_pod.zip -d f:/perllib/lib

This is used by by perldoc program (see the perldoc manpage), and may be used to generate HTML documentation usable by WWW browsers, and documentation in zillions of other formats: info, LaTeX, Acrobat, FrameMaker and so on.

Perl manual in .INF format

  unzip perl_inf.zip -d d:/os2/book

This directory should better be on BOOKSHELF.

Pdksh

  unzip perl_sh.zip -d f:/bin

This is used by perl to run external commands which explicitly require shell, like the commands using redirection and shell metacharacters. It is also used instead of explicit /bin/sh.

Set PERL_SH_DIR (see PERL_SH_DIR) if you move sh.exe from the above location.

Note. It may be possible to use some other sh-compatible shell (not tested).

After you installed the components you needed and updated the Config.sys correspondingly, you need to hand-edit Config.pm. This file resides somewhere deep in the location you installed your perl library, find it out by

  perl -MConfig -le "print $INC{'Config.pm'}"

You need to correct all the entries which look like file paths (they currently start with f:/).


Warning

The automatic and manual perl installation leave precompiled paths inside perl executables. While these paths are overwriteable (see PERLLIB_PREFIX, PERL_SH_DIR), one may get better results by binary editing of paths inside the executables/DLLs.


Accessing documentation

Depending on how you built/installed perl you may have (otherwise identical) Perl documentation in the following formats:


OS/2 .INF file

Most probably the most convenient form. Under OS/2 view it as

  view perl
  view perl perlfunc
  view perl less
  view perl ExtUtils::MakeMaker

(currently the last two may hit a wrong location, but this may improve soon). Under Win* see SYNOPSIS.

If you want to build the docs yourself, and have OS/2 toolkit, run

        pod2ipf > perl.ipf

in /perllib/lib/pod directory, then

        ipfc /inf perl.ipf

(Expect a lot of errors during the both steps.) Now move it on your BOOKSHELF path.


Plain text

If you have perl documentation in the source form, perl utilities installed, and GNU groff installed, you may use

        perldoc perlfunc
        perldoc less
        perldoc ExtUtils::MakeMaker

to access the perl documentation in the text form (note that you may get better results using perl manpages).

Alternately, try running pod2text on .pod files.


Manpages

If you have man installed on your system, and you installed perl manpages, use something like this:

        man perlfunc
        man 3 less
        man ExtUtils.MakeMaker

to access documentation for different components of Perl. Start with

        man perl

Note that dot (.) is used as a package separator for documentation for packages, and as usual, sometimes you need to give the section - 3 above - to avoid shadowing by the less(1) manpage.

Make sure that the directory above the directory with manpages is on our MANPATH, like this

  set MANPATH=c:/man;f:/perllib/man


HTML

If you have some WWW browser available, installed the Perl documentation in the source form, and Perl utilities, you can build HTML docs. Cd to directory with .pod files, and do like this

        cd f:/perllib/lib/pod
        pod2html

After this you can direct your browser the file perl.html in this directory, and go ahead with reading docs, like this:

        explore file:///f:/perllib/lib/pod/perl.html

Alternatively you may be able to get these docs prebuilt from CPAN.


GNU info files

Users of Emacs would appreciate it very much, especially with CPerl mode loaded. You need to get latest pod2info from CPAN, or, alternately, prebuilt info pages.


.PDF files

for Acrobat are available on CPAN (for slightly old version of perl).


LaTeX docs

can be constructed using pod2latex.


BUILD

Here we discuss how to build Perl under OS/2. There is an alternative (but maybe older) view on http:.


Prerequisites

You need to have the latest EMX development environment, the full GNU tool suite (gawk renamed to awk, and GNU find.exe earlier on path than the OS/2 find.exe, same with sort.exe, to check use

  find --version
  sort --version

). You need the latest version of pdksh installed as sh.exe.

Check that you have BSD libraries and headers installed, and - optionally - Berkeley DB headers and libraries, and crypt.

Possible locations to get this from are

  ftp://hobbes.nmsu.edu/os2/unix/
  ftp://ftp.cdrom.com/pub/os2/unix/
  ftp://ftp.cdrom.com/pub/os2/dev32/
  ftp://ftp.cdrom.com/pub/os2/emx09c/

It is reported that the following archives contain enough utils to build perl: gnufutil.zip, gnusutil.zip, gnututil.zip, gnused.zip, gnupatch.zip, gnuawk.zip, gnumake.zip and ksh527rt.zip. Note that all these utilities are known to be available from LEO:

  ftp://ftp.leo.org/pub/comp/os/os2/leo/gnu

Make sure that no copies or perl are currently running. Later steps of the build may fail since an older version of perl.dll loaded into memory may be found.

Also make sure that you have /tmp directory on the current drive, and . directory in your LIBPATH. One may try to correct the latter condition by

  set BEGINLIBPATH .

if you use something like CMD.EXE or latest versions of 4os2.exe.

Make sure your gcc is good for -Zomf linking: run omflibs script in /emx/lib directory.

Check that you have link386 installed. It comes standard with OS/2, but may be not installed due to customization. If typing

  link386

shows you do not have it, do Selective install, and choose Link object modules in Optional system utilities/More. If you get into link386, press Ctrl-C.


Getting perl source

You need to fetch the latest perl source (including developers releases). With some probability it is located in

  http://www.perl.com/CPAN/src/5.0
  http://www.perl.com/CPAN/src/5.0/unsupported

If not, you may need to dig in the indices to find it in the directory of the current maintainer.

Quick cycle of developers release may break the OS/2 build time to time, looking into

  http://www.perl.com/CPAN/ports/os2/ilyaz/

may indicate the latest release which was publicly released by the maintainer. Note that the release may include some additional patches to apply to the current source of perl.

Extract it like this

  tar vzxf perl5.00409.tar.gz

You may see a message about errors while extracting Configure. This is because there is a conflict with a similarly-named file configure.

Change to the directory of extraction.


Application of the patches

You need to apply the patches in ./os2/diff.* and ./os2/POSIX.mkfifo like this:

  gnupatch -p0 < os2\POSIX.mkfifo
  gnupatch -p0 < os2\diff.configure

You may also need to apply the patches supplied with the binary distribution of perl.

Note also that the db.lib and db.a from the EMX distribution are not suitable for multi-threaded compile (note that currently perl is not multithread-safe, but is compiled as multithreaded for compatibility with XFree86-OS/2). Get a corrected one from

  ftp://ftp.math.ohio-state.edu/pub/users/ilya/os2/db_mt.zip

To make -p filetest work, one may also need to apply the following patch to EMX headers:

  --- /emx/include/sys/stat.h.orig      Thu May 23 13:48:16 1996
  +++ /emx/include/sys/stat.h   Sun Jul 12 14:11:32 1998
  @@ -53,7 +53,7 @@ struct stat
   #endif
 
   #if !defined (S_IFMT)
  -#define S_IFMT   0160000  /* Mask for file type */
  +#define S_IFMT   0170000  /* Mask for file type */
   #define S_IFIFO  0010000  /* Pipe */
   #define S_IFCHR  0020000  /* Character device */
   #define S_IFDIR  0040000  /* Directory */


Hand-editing

You may look into the file ./hints/os2.sh and correct anything wrong you find there. I do not expect it is needed anywhere.


Making

  sh Configure -des -D prefix=f:/perllib

prefix means: where to install the resulting perl library. Giving correct prefix you may avoid the need to specify PERLLIB_PREFIX, see PERLLIB_PREFIX.

Ignore the message about missing ln, and about -c option to tr. In fact if you can trace where the latter spurious warning comes from, please inform me.

Now

  make

At some moment the built may die, reporting a version mismatch or unable to run perl. This means that most of the build has been finished, and it is the time to move the constructed perl.dll to some absolute location in LIBPATH. After this is done the build should finish without a lot of fuss. One can avoid the interruption if one has the correct prebuilt version of perl.dll on LIBPATH, but probably this is not needed anymore, since miniperl.exe is linked statically now.

Warnings which are safe to ignore: mkfifo() redefined inside POSIX.c.


Testing

If you haven't yet moved perl.dll onto LIBPATH, do it now (alternatively, if you have a previous perl installation you'd rather not disrupt until this one is installed, copy perl.dll to the t directory).

Now run

  make test

All tests should succeed (with some of them skipped). Note that on one of the systems I see intermittent failures of io/pipe.t subtest 9. Any help to track what happens with this test is appreciated.

Some tests may generate extra messages similar to

A lot of bad free

in database tests related to Berkeley DB. This is a confirmed bug of DB. You may disable this warnings, see PERL_BADFREE.

There is not much we can do with it (but apparently it does not cause any real error with data).

Process terminated by SIGTERM/SIGINT

This is a standard message issued by OS/2 applications. *nix applications die in silence. It is considered a feature. One can easily disable this by appropriate sighandlers.

However the test engine bleeds these message to screen in unexpected moments. Two messages of this kind should be present during testing.

Two lib/io_* tests may generate popups (system error SYS3175), but should succeed anyway. This is due to a bug of EMX related to fork()ing with dynamically loaded libraries.

I submitted a patch to EMX which makes it possible to fork() with EMX dynamic libraries loaded, which makes lib/io* tests pass without skipping offended tests. This means that soon the number of skipped tests may decrease yet more.

To get finer test reports, call

  perl t/harness

The report with io/pipe.t failing may look like this:

  Failed Test  Status Wstat Total Fail  Failed  List of failed
  ------------------------------------------------------------
  io/pipe.t                    12    1   8.33%  9
  7 tests skipped, plus 56 subtests skipped.
  Failed 1/195 test scripts, 99.49% okay. 1/6542 subtests failed, 99.98% okay.

The reasons for most important skipped tests are:

op/fs.t
  • 8

    Checks atime and mtime of stat() - unfortunately, HPFS provides only 2sec time granularity (for compatibility with FAT?).

  • 5 Checks truncate() on a filehandle just opened for write - I do not know why this should or should not work.
  • lib/io_pipe.t

    Checks IO::Pipe module. Some feature of EMX - test fork()s with dynamic extension loaded - unsupported now.

    lib/io_sock.t

    Checks IO::Socket module. Some feature of EMX - test fork()s with dynamic extension loaded - unsupported now.

    op/stat.t

    Checks stat(). Tests:
    1. Checks atime and mtime of stat() - unfortunately, HPFS provides only 2sec time granularity (for compatibility with FAT?).

    lib/io_udp.t

    It never terminates, apparently some bug in storing the last socket from which we obtained a message.


    Installing the built perl

    If you haven't yet moved perl.dll onto LIBPATH, do it now.

    Run

      make install
    

    It would put the generated files into needed locations. Manually put perl.exe, perl__.exe and perl___.exe to a location on your PATH, perl.dll to a location on your LIBPATH.

    Run

      make cmdscripts INSTALLCMDDIR=d:/ir/on/path
    

    to convert perl utilities to .cmd files and put them on PATH. You need to put .EXE-utilities on path manually. They are installed in $prefix/bin, here $prefix is what you gave to Configure, see Making.


    a.out-style build

    Proceed as above, but make perl_.exe (see perl_.exe) by

      make perl_
    

    test and install by

      make aout_test
      make aout_install
    

    Manually put perl_.exe to a location on your PATH.

    Since perl_ has the extensions prebuilt, it does not suffer from the dynamic extensions + fork() syndrome, thus the failing tests look like

      Failed Test  Status Wstat Total Fail  Failed  List of failed
      ---------------------------------------------------------------
      io/fs.t                      26   11  42.31%  2-5, 7-11, 18, 25
      op/stat.t                    56    5   8.93%  3-4, 20, 35, 39
      Failed 2/118 test scripts, 98.31% okay. 16/2445 subtests failed, 99.35% okay.
    

    Note. The build process for perl_ does not know about all the dependencies, so you should make sure that anything is up-to-date, say, by doing

      make perl.dll
    

    first.


    Build FAQ


    Some / became \ in pdksh.

    You have a very old pdksh. See Prerequisites.


    'errno' - unresolved external

    You do not have MT-safe db.lib. See Prerequisites.


    Problems with tr or sed

    reported with very old version of tr and sed.


    Some problem (forget which ;-)

    You have an older version of perl.dll on your LIBPATH, which broke the build of extensions.


    Library ... not found

    You did not run omflibs. See Prerequisites.


    Segfault in make

    You use an old version of GNU make. See Prerequisites.


    Specific (mis)features of OS/2 port


    setpriority, getpriority

    Note that these functions are compatible with *nix, not with the older ports of '94 - 95. The priorities are absolute, go from 32 to -95, lower is quicker. 0 is the default priority.


    system()

    Multi-argument form of system() allows an additional numeric argument. The meaning of this argument is described in Process.


    extproc on the first line

    If the first chars of a script are "extproc ", this line is treated as #!-line, thus all the switches on this line are processed (twice if script was started via cmd.exe).


    Additional modules:

    Process, REXX, PrfDB, ExtAttr. These modules provide access to additional numeric argument for system and to the list of the running processes, to DLLs having functions with REXX signature and to REXX runtime, to OS/2 databases in the .INI format, and to Extended Attributes.

    Two additional extensions by Andreas Kaiser, OS2::UPM, and OS2::FTP, are included into my ftp directory, mirrored on CPAN.


    Prebuilt methods:

    File::Copy::syscopy

    used by File::Copy::copy, see Copy.

    DynaLoader::mod2fname

    used by DynaLoader for DLL name mangling.

    Cwd::current_drive()

    Self explanatory.

    Cwd::sys_chdir(name)

    leaves drive as it is.

    Cwd::change_drive(name)
    Cwd::sys_is_absolute(name)

    means has drive letter and is_rooted.

    Cwd::sys_is_rooted(name)

    means has leading [/\\] (maybe after a drive-letter:).

    Cwd::sys_is_relative(name)

    means changes with current dir.

    Cwd::sys_cwd(name)

    Interface to cwd from EMX. Used by Cwd::cwd.

    Cwd::sys_abspath(name, dir)

    Really really odious function to implement. Returns absolute name of file which would have name if CWD were dir. Dir defaults to the current dir.

    C<Cwd::extLibpath([type])

    Get current value of extended library search path. If type is present and true, works with END_LIBPATH, otherwise with BEGIN_LIBPATH.

    Cwd::extLibpath_set( path [, type ] )

    Set current value of extended library search path. If type is present and true, works with END_LIBPATH, otherwise with BEGIN_LIBPATH.

    (Note that some of these may be moved to different libraries - eventually).


    Misfeatures

    Since flock(3) is present in EMX, but is not functional, it is emulated by perl. To disable the emulations, set environment variable USE_PERL_FLOCK=0.

    Here is the list of things which may be ``broken'' on EMX (from EMX docs):