Adjust docs to reflect that DynaLoader, as of change 27549,

[perl5.git] / lib / FileCache.pm

diff --git a/lib/FileCache.pm b/lib/FileCache.pm
index 8e1fe44..02bde7e 100644 (file)
--- a/lib/FileCache.pm
+++ b/lib/FileCache.pm
@@ -1,6 +1,6 @@
 package FileCache;
 
-our $VERSION = 1.03;
+our $VERSION = '1.06';
 
 =head1 NAME
 
@@ -46,9 +46,14 @@ and subsequent openings. Most valid modes for 3-argument C<open> are supported
 namely; C<< '>' >>, C<< '+>' >>, C<< '<' >>, C<< '<+' >>, C<<< '>>' >>>,
 C< '|-' > and C< '-|' >
 
+To pass supplemental arguments to a program opened with C< '|-' > or C< '-|' >
+append them to the command string as you would system EXPR.
+
 Returns EXPR on success for convenience. You may neglect the
 return value and manipulate EXPR as the filehandle directly if you prefer.
 
+=back
+
 =head1 CAVEATS
 
 While it is permissible to C<close> a FileCache managed file,
@@ -56,18 +61,21 @@ do not do so if you are calling C<FileCache::cacheout> from a package other
 than which it was imported, or with another module which overrides C<close>.
 If you must, use C<FileCache::cacheout_close>.
 
+Although FileCache can be used with piped opens ('-|' or '|-') doing so is
+strongly discouraged.  If FileCache finds it necessary to close and then reopen
+a pipe, the command at the far end of the pipe will be reexecuted - the results
+of performing IO on FileCache'd pipes is unlikely to be what you expect.  The
+ability to use FileCache on pipes may be removed in a future release.
+
+FileCache does not store the current file offset if it finds it necessary to
+close a file.  When the file is reopened, the offset will be as specified by the
+original C<open> file mode.  This could be construed to be a bug.
+
 =head1 BUGS
 
 F<sys/param.h> lies with its C<NOFILE> define on some systems,
 so you may have to set I<maxopen> yourself.
 
-=head1 NOTES
-
-FileCache installs signal handlers for CHLD (a.k.a. CLD) and PIPE in the
-calling package to handle deceased children from 2-arg C<cacheout> with C<'|-'>
-or C<'-|'> I<expediently>. The children would otherwise be reaped eventually,
-unless you terminated before repeatedly calling cacheout.
-
 =cut
 
 require 5.006;
@@ -75,26 +83,35 @@ use Carp;
 use Config;
 use strict;
 no strict 'refs';
+
 # These are not C<my> for legacy reasons.
 # Previous versions requested the user set $cacheout_maxopen by hand.
 # Some authors fiddled with %saw to overcome the clobber on initial open.
 use vars qw(%saw $cacheout_maxopen);
+$cacheout_maxopen = 16;
+
+use base 'Exporter';
+our @EXPORT = qw[cacheout cacheout_close];
+
+
 my %isopen;
 my $cacheout_seq = 0;
 
 sub import {
     my ($pkg,%args) = @_;
-    $pkg = caller(1);
-    *{$pkg.'::cacheout'} = \&cacheout;
-    *{$pkg.'::close'}    = \&cacheout_close;
 
-    # Reap our children
-    ${"$pkg\::SIG"}{'CLD'}  = 'IGNORE' if $Config{sig_name} =~ /\bCLD\b/;
-    ${"$pkg\::SIG"}{'CHLD'} = 'IGNORE' if $Config{sig_name} =~ /\bCHLD\b/;
-    ${"$pkg\::SIG"}{'PIPE'} = 'IGNORE' if $Config{sig_name} =~ /\bPIPE\b/;
+    # Use Exporter. %args are for us, not Exporter.
+    # Make sure to up export_to_level, or we will import into ourselves,
+    # rather than our calling package;
+
+    __PACKAGE__->export_to_level(1);
+    Exporter::import( $pkg );
 
     # Truth is okay here because setting maxopen to 0 would be bad
     return $cacheout_maxopen = $args{maxopen} if $args{maxopen};
+
+    # XXX This code is crazy.  Why is it a one element foreach loop?
+    # Why is it using $param both as a filename and filehandle?
     foreach my $param ( '/usr/include/sys/param.h' ){
       if (open($param, '<', $param)) {
        local ($_, $.);
@@ -135,12 +152,12 @@ sub cacheout {
     ($file, $mode) = ($mode, $file) if $narg == 1;
     croak "Invalid mode for cacheout" if $mode &&
       ( $mode !~ /^\s*(?:>>|\+?>|\+?<|\|\-|)|\-\|\s*$/ );
-    
+
     # Mode changed?
-    if( $isopen{$file} && ($mode||'>') ne $isopen{$file}->[2] ){
+    if( $isopen{$file} && ($mode||'>') ne $isopen{$file}->[1] ){
       &cacheout_close($file, 1);
     }
-    
+
     if( $isopen{$file}) {
       $ret = $file;
       $isopen{$file}->[0]++;
@@ -159,7 +176,7 @@ sub cacheout {
       }
       #XXX should we just return the value from cacheout_open, no croak?
       $ret = cacheout_open($mode, $file) or croak("Can't create $file: $!");
-      
+
       $isopen{$file} = [++$cacheout_seq, $mode];
     }
     return $ret;