summaryrefslogtreecommitdiff
path: root/lib/Autom4te/XFile.pm
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Autom4te/XFile.pm')
-rw-r--r--lib/Autom4te/XFile.pm319
1 files changed, 319 insertions, 0 deletions
diff --git a/lib/Autom4te/XFile.pm b/lib/Autom4te/XFile.pm
new file mode 100644
index 0000000..28d5bc6
--- /dev/null
+++ b/lib/Autom4te/XFile.pm
@@ -0,0 +1,319 @@
+# Copyright (C) 2001-2012 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Written by Akim Demaille <akim@freefriends.org>.
+
+###############################################################
+# The main copy of this file is in Automake's git repository. #
+# Updates should be sent to automake-patches@gnu.org. #
+###############################################################
+
+package Autom4te::XFile;
+
+=head1 NAME
+
+Autom4te::XFile - supply object methods for filehandles with error handling
+
+=head1 SYNOPSIS
+
+ use Autom4te::XFile;
+
+ $fh = new Autom4te::XFile;
+ $fh->open ("< file");
+ # No need to check $FH: we died if open failed.
+ print <$fh>;
+ $fh->close;
+ # No need to check the return value of close: we died if it failed.
+
+ $fh = new Autom4te::XFile "> file";
+ # No need to check $FH: we died if new failed.
+ print $fh "bar\n";
+ $fh->close;
+
+ $fh = new Autom4te::XFile "file", "r";
+ # No need to check $FH: we died if new failed.
+ defined $fh
+ print <$fh>;
+ undef $fh; # automatically closes the file and checks for errors.
+
+ $fh = new Autom4te::XFile "file", O_WRONLY | O_APPEND;
+ # No need to check $FH: we died if new failed.
+ print $fh "corge\n";
+
+ $pos = $fh->getpos;
+ $fh->setpos ($pos);
+
+ undef $fh; # automatically closes the file and checks for errors.
+
+ autoflush STDOUT 1;
+
+=head1 DESCRIPTION
+
+C<Autom4te::XFile> inherits from C<IO::File>. It provides the method
+C<name> returning the file name. It provides dying versions of the
+methods C<close>, C<lock> (corresponding to C<flock>), C<new>,
+C<open>, C<seek>, and C<truncate>. It also overrides the C<getline>
+and C<getlines> methods to translate C<\r\n> to C<\n>.
+
+=cut
+
+use 5.006;
+use strict;
+use vars qw($VERSION @EXPORT @EXPORT_OK $AUTOLOAD @ISA);
+use Carp;
+use Errno;
+use IO::File;
+use File::Basename;
+use Autom4te::ChannelDefs;
+use Autom4te::Channels qw(msg);
+use Autom4te::FileUtils;
+
+require Exporter;
+require DynaLoader;
+
+@ISA = qw(IO::File Exporter DynaLoader);
+
+$VERSION = "1.2";
+
+@EXPORT = @IO::File::EXPORT;
+
+eval {
+ # Make all Fcntl O_XXX and LOCK_XXX constants available for importing
+ require Fcntl;
+ my @O = grep /^(LOCK|O)_/, @Fcntl::EXPORT, @Fcntl::EXPORT_OK;
+ Fcntl->import (@O); # first we import what we want to export
+ push (@EXPORT, @O);
+};
+
+=head2 Methods
+
+=over
+
+=item C<$fh = new Autom4te::XFile ([$expr, ...]>
+
+Constructor a new XFile object. Additional arguments
+are passed to C<open>, if any.
+
+=cut
+
+sub new
+{
+ my $type = shift;
+ my $class = ref $type || $type || "Autom4te::XFile";
+ my $fh = $class->SUPER::new ();
+ if (@_)
+ {
+ $fh->open (@_);
+ }
+ $fh;
+}
+
+=item C<$fh-E<gt>open ([$file, ...])>
+
+Open a file, passing C<$file> and further arguments to C<IO::File::open>.
+Die if opening fails. Store the name of the file. Use binmode for writing.
+
+=cut
+
+sub open
+{
+ my $fh = shift;
+ my ($file) = @_;
+
+ # WARNING: Gross hack: $FH is a typeglob: use its hash slot to store
+ # the 'name' of the file we are opening. See the example with
+ # io_socket_timeout in IO::Socket for more, and read Graham's
+ # comment in IO::Handle.
+ ${*$fh}{'autom4te_xfile_file'} = "$file";
+
+ if (!$fh->SUPER::open (@_))
+ {
+ fatal "cannot open $file: $!";
+ }
+
+ # In case we're running under MSWindows, don't write with CRLF.
+ # (This circumvents a bug in at least Cygwin bash where the shell
+ # parsing fails on lines ending with the continuation character '\'
+ # and CRLF).
+ binmode $fh if $file =~ /^\s*>/;
+}
+
+=item C<$fh-E<gt>close>
+
+Close the file, handling errors.
+
+=cut
+
+sub close
+{
+ my $fh = shift;
+ if (!$fh->SUPER::close (@_))
+ {
+ my $file = $fh->name;
+ Autom4te::FileUtils::handle_exec_errors $file
+ unless $!;
+ fatal "cannot close $file: $!";
+ }
+}
+
+=item C<$line = $fh-E<gt>getline>
+
+Read and return a line from the file. Ensure C<\r\n> is translated to
+C<\n> on input files.
+
+=cut
+
+# Some native Windows/perl installations fail to translate \r\n to \n on
+# input so we do that here.
+sub getline
+{
+ local $_ = $_[0]->SUPER::getline;
+ # Perform a _global_ replacement: $_ may can contains many lines
+ # in slurp mode ($/ = undef).
+ s/\015\012/\n/gs if defined $_;
+ return $_;
+}
+
+=item C<@lines = $fh-E<gt>getlines>
+
+Slurp lines from the files.
+
+=cut
+
+sub getlines
+{
+ my @res = ();
+ my $line;
+ push @res, $line while $line = $_[0]->getline;
+ return @res;
+}
+
+=item C<$name = $fh-E<gt>name>
+
+Return the name of the file.
+
+=cut
+
+sub name
+{
+ my $fh = shift;
+ return ${*$fh}{'autom4te_xfile_file'};
+}
+
+=item C<$fh-E<gt>lock>
+
+Lock the file using C<flock>. If locking fails for reasons other than
+C<flock> being unsupported, then error out if C<$ENV{'MAKEFLAGS'}> indicates
+that we are spawned from a parallel C<make>.
+
+=cut
+
+sub lock
+{
+ my ($fh, $mode) = @_;
+ # Cannot use @_ here.
+
+ # Unless explicitly configured otherwise, Perl implements its 'flock' with the
+ # first of flock(2), fcntl(2), or lockf(3) that works. These can fail on
+ # NFS-backed files, with ENOLCK (GNU/Linux) or EOPNOTSUPP (FreeBSD); we
+ # usually ignore these errors. If $ENV{MAKEFLAGS} suggests that a parallel
+ # invocation of 'make' has invoked the tool we serve, report all locking
+ # failures and abort.
+ #
+ # On Unicos, flock(2) and fcntl(2) over NFS hang indefinitely when 'lockd' is
+ # not running. NetBSD NFS clients silently grant all locks. We do not
+ # attempt to defend against these dangers.
+ #
+ # -j is for parallel BSD make, -P is for parallel HP-UX make.
+ if (!flock ($fh, $mode))
+ {
+ my $make_j = (exists $ENV{'MAKEFLAGS'}
+ && " -$ENV{'MAKEFLAGS'}" =~ / (-[BdeikrRsSw]*[jP]|--[jP]|---?jobs)/);
+ my $note = "\nforgo \"make -j\" or use a file system that supports locks";
+ my $file = $fh->name;
+
+ msg ($make_j ? 'fatal' : 'unsupported',
+ "cannot lock $file with mode $mode: $!" . ($make_j ? $note : ""))
+ if $make_j || !($!{ENOLCK} || $!{EOPNOTSUPP});
+ }
+}
+
+=item C<$fh-E<gt>seek ($position, [$whence])>
+
+Seek file to C<$position>. Die if seeking fails.
+
+=cut
+
+sub seek
+{
+ my $fh = shift;
+ # Cannot use @_ here.
+ if (!seek ($fh, $_[0], $_[1]))
+ {
+ my $file = $fh->name;
+ fatal "cannot rewind $file with @_: $!";
+ }
+}
+
+=item C<$fh-E<gt>truncate ($len)>
+
+Truncate the file to length C<$len>. Die on failure.
+
+=cut
+
+sub truncate
+{
+ my ($fh, $len) = @_;
+ if (!truncate ($fh, $len))
+ {
+ my $file = $fh->name;
+ fatal "cannot truncate $file at $len: $!";
+ }
+}
+
+=back
+
+=head1 SEE ALSO
+
+L<perlfunc>,
+L<perlop/"I/O Operators">,
+L<IO::File>
+L<IO::Handle>
+L<IO::Seekable>
+
+=head1 HISTORY
+
+Derived from IO::File.pm by Akim Demaille E<lt>F<akim@freefriends.org>E<gt>.
+
+=cut
+
+1;
+
+### Setup "GNU" style for perl-mode and cperl-mode.
+## Local Variables:
+## perl-indent-level: 2
+## perl-continued-statement-offset: 2
+## perl-continued-brace-offset: 0
+## perl-brace-offset: 0
+## perl-brace-imaginary-offset: 0
+## perl-label-offset: -2
+## cperl-indent-level: 2
+## cperl-brace-offset: 0
+## cperl-continued-brace-offset: 0
+## cperl-label-offset: -2
+## cperl-extra-newline-before-brace: t
+## cperl-merge-trailing-else: nil
+## cperl-continued-statement-offset: 2
+## End: