From: Chris Nandor Date: Sat, 19 Dec 1998 12:54:34 +0000 (-0500) Subject: perlport.pod v1.37 X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3c075c7de87f20129c6bd1b21ce4871ba78b3ca2;p=p5sagit%2Fp5-mst-13.2.git perlport.pod v1.37 To: perl5-porters@perl.org Message-Id: p4raw-id: //depot/cfgperl@2494 --- diff --git a/pod/perlport.pod b/pod/perlport.pod index 06c993b..6faa0d0 100644 --- a/pod/perlport.pod +++ b/pod/perlport.pod @@ -189,7 +189,7 @@ root directory. VMS, Windows, and OS/2 can work similarly to Unix with C as path separator, or in their own idiosyncratic ways (such as having several -root directories and various "unrooted" device files such NIL: and +root directories and various "unrooted" device files such NIL: and LPT:). S uses C<:> as a path separator instead of C. @@ -228,19 +228,21 @@ Also of use is C, from the standard distribution, which splits a pathname into pieces (base filename, full path to directory, and file suffix). -Even when on a single platform (if you can call UNIX a single -platform), remember not to count on the existence or the contents of -system-specific files, like F, F, or -F. For example the F may exist but it -may not contain the encrypted passwords because the system is using -some form of enhanced security-- or it may not contain all the -accounts because the system is using NIS. If code does need to rely -on such a file, include a description of the file and its format in -the code's documentation, and make it easy for the user to override -the default location of the file. +Even when on a single platform (if you can call UNIX a single platform), +remember not to count on the existence or the contents of +system-specific files or directories, like F, +F, F, or even F. For +example, F may exist but it may not contain the encrypted +passwords because the system is using some form of enhanced security -- +or it may not contain all the accounts because the system is using NIS. +If code does need to rely on such a file, include a description of the +file and its format in the code's documentation, and make it easy for +the user to override the default location of the file. + +Don't assume a text file will end with a newline. Do not have two files of the same name with different case, like -F and , as many platforms have case-insensitive +F and F, as many platforms have case-insensitive filenames. Also, try not to have non-word characters (except for C<.>) in the names, and keep them to the 8.3 convention, for maximum portability. @@ -250,11 +252,14 @@ Likewise, if using C, try to keep the split functions to make it so the resulting files have a unique (case-insensitively) first 8 characters. -Don't assume C> won't be the first character of a filename. Always -use C> explicitly to open a file for reading: +Don't assume C> won't be the first character of a filename. Always +use C> explicitly to open a file for reading. open(FILE, "<$existing_file") or die $!; +Actually, though, if filenames might use strange characters, it is +safest to open it with C instead of C, which is magic. + =head2 System Interaction @@ -284,6 +289,8 @@ C instead. Don't count on per-program environment variables, or per-program current directories. +Don't count on specific values of C<$!>. + =head2 Interprocess Communication (IPC) @@ -320,6 +327,7 @@ code, but expose a common interface). The UNIX System V IPC (C) is not available even in all UNIX platforms. + =head2 External Subroutines (XS) XS code, in general, can be made to work with any platform; but dependent @@ -375,7 +383,7 @@ C. Assume very little about character sets. Do not assume anything about the numerical values (C, C) of characters. Do not assume that the alphabetic characters are encoded contiguously (in -numerical sense). Do no assume anything about the ordering of the +numerical sense). Do not assume anything about the ordering of the characters. The lowercase letters may come before or after the uppercase letters, the lowercase and uppercase may be interlaced so that both 'a' and 'A' come before the 'b', the accented and other @@ -385,10 +393,10 @@ before the 'b'. =head2 Internationalisation -If you may assume POSIX (a rather large assumption, that: in practise -that means UNIX) you may read more about the POSIX locale system from +If you may assume POSIX (a rather large assumption, that in practice +means UNIX), you may read more about the POSIX locale system from L. The locale system at least attempts to make things a -little bit more portable or at least more convenient and +little bit more portable, or at least more convenient and native-friendly for non-English users. The system affects character sets and encoding, and date and time formatting, among other things. @@ -480,7 +488,7 @@ Unix flavors: FreeBSD freebsd freebsd-i386 Linux linux i386-linux HP-UX hpux PA-RISC1.1 - IRIX irix irix + IRIX irix irix OSF1 dec_osf alpha-dec_osf SunOS solaris sun4-solaris SunOS solaris i86pc-solaris @@ -582,7 +590,7 @@ limited to 31 characters, and may include any character except C<:>, which is reserved as a path separator. Instead of C, see C and C in the -C module. +C module, or C and C. In the MacPerl application, you can't run a program from the command line; programs that expect C<@ARGV> to be populated can be edited with something @@ -617,10 +625,9 @@ the application or MPW tool version is running, check: $is_ppc = $MacPerl::Architecture eq 'MacPPC'; $is_68k = $MacPerl::Architecture eq 'Mac68K'; -S, to be based on NeXT's OpenStep OS, will be able to run -MacPerl natively (in the Blue Box, and even in the Yellow Box, once some -changes to the toolbox calls are made), but Unix perl will also run -natively. +S, to be based on NeXT's OpenStep OS, will (in theory) be able +to run MacPerl natively, but Unix perl will also run natively under the +built-in Unix environment. Also see: @@ -833,6 +840,7 @@ C<\r> is the same under both Unix and OS/390 & VM/ESA): The value of C<$^O> on OS/390 is "os390". The value of C<$^O> on VM/ESA is "vmesa". + Some simple tricks for determining if you are running on an EBCDIC platform could include any of the following (perhaps all): @@ -905,7 +913,7 @@ C contains a single item list. The filesystem will also expand system variables in filenames if enclosed in angle brackets, so CSystem$DirE.Modules> would look for the file S>. The obvious implication of this is -that BE> and should +that BE>> and should be protected when C is used for input. Because C<.> was in use as a directory separator and filenames could not @@ -1126,6 +1134,7 @@ Invokes VMS debugger. (VMS) Not implemented. (S) Implemented via Spawn. (VM/ESA) + =item fcntl FILEHANDLE,FUNCTION,SCALAR Not implemented. (Win32, VMS) @@ -1491,23 +1500,34 @@ Not useful. (S) =over 4 -=item 1.35, 9 September 1998 +=item v1.37, 19 December 1998 + +More minor changes. Merge two separate version 1.35 documents. + +=item v1.36, 9 September 1998 + +Updated for Stratus VOS. Also known as version 1.35. + +=item v1.35, 13 August 1998 -Updated for Stratus VOS. +Integrate more minor changes, plus addition of new sections under +L<"ISSUES">: L<"Numbers endianness and Width">, +L<"Character sets and character encoding">, +L<"Internationalisation">. -=item 1.33, 06 August 1998 +=item v1.33, 06 August 1998 Integrate more minor changes. -=item 1.32, 05 August 1998 +=item v1.32, 05 August 1998 Integrate more minor changes. -=item 1.30, 03 August 1998 +=item v1.30, 03 August 1998 Major update for RISC OS, other minor changes. -=item 1.23, 10 July 1998 +=item v1.23, 10 July 1998 First public release with perl5.005. @@ -1529,6 +1549,7 @@ Jarkko Hietaniemi Ejhi@iki.fi, Luther Huffman Elutherh@stratcom.comE, Nick Ing-Simmons Enick@ni-s.u-net.comE, Andreas J. KEnig Ekoenig@kulturbox.deE, +Markus Laker Emlaker@contax.co.ukE, Andrew M. Langmead Eaml@world.std.comE, Paul Moore EPaul.Moore@uk.origin-it.comE, Chris Nandor Epudge@pobox.comE, @@ -1542,9 +1563,10 @@ Paul J. Schinder Eschinder@pobox.comE, Dan Sugalski Esugalskd@ous.eduE, Nathan Torkington Egnat@frii.comE. -This document is maintained by Chris Nandor. +This document is maintained by Chris Nandor +Epudge@pobox.comE. =head1 VERSION -Version 1.35, last modified 09 September 1998. +Version 1.37, last modified 19 December 1998