=head2 Wildcard expansion
File specifications containing wildcards are allowed both on
-the command line and within Perl globs (e.g. <CE<lt>*.cE<gt>>). If
+the command line and within Perl globs (e.g. C<E<lt>*.cE<gt>>). If
the wildcard filespec uses VMS syntax, the resultant
filespecs will follow VMS syntax; if a Unix-style filespec is
passed in, Unix-style filespecs will be returned.
argument to the C<system> operator (see below). In this case,
Perl will wait for the subprocess to complete before continuing.
+The mailbox (MBX) that perl can create to communicate with a pipe
+defaults to a buffer size of 512. The default buffer size is
+adjustable via the logical name PERL_MBX_SIZE provided that the
+value falls between 128 and the SYSGEN parameter MAXBUF inclusive.
+For example, to double the MBX size from the default within
+a Perl program, use C<$ENV{'PERL_MBX_SIZE'} = 1024;> and then
+open and use pipe constructs. An alternative would be to issue
+the command:
+
+ $ Define PERL_MBX_SIZE 1024
+
+before running your wide record pipe program. A larger value may
+improve performance at the expense of the BYTLM UAF quota.
+
=head1 PERL5LIB and PERLLIB
The PERL5LIB and PERLLIB logical names work as documented in L<perl>,
Perl for VMS supports redirection of input and output on the
command line, using a subset of Bourne shell syntax:
- <F<file> reads stdin from F<file>,
- >F<file> writes stdout to F<file>,
- >>F<file> appends stdout to F<file>,
- 2>F<file> writes stderr to F<file>, and
- 2>>F<file> appends stderr to F<file>.
+=over
+
+=item *
+
+C<E<lt>file> reads stdin from C<file>,
+
+=item *
+
+C<E<gt>file> writes stdout to C<file>,
+
+=item *
+
+C<E<gt>E<gt>file> appends stdout to C<file>,
+
+=item *
+
+C<2E<gt>file> writes stderr to C<file>, and
+
+=item *
+
+C<2E<gt>E<gt>file> appends stderr to C<file>.
+
+=back
In addition, output may be piped to a subprocess, using the
character '|'. Anything after this character on the command
=item -S
-If the C<-S> switch is present I<and> the script name does
-not contain a directory, then Perl translates the logical
-name DCL$PATH as a searchlist, using each translation as
-a directory in which to look for the script. In addition,
+If the C<"-S"> or C<-"S"> switch is present I<and> the script
+name does not contain a directory, then Perl translates the
+logical name DCL$PATH as a searchlist, using each translation
+as a directory in which to look for the script. In addition,
if no file type is specified, Perl looks in each directory
for a file matching the name specified, with a blank type,
a type of F<.pl>, and a type of F<.com>, in that order.
password strings; you'll have to upcase the arguments to
C<crypt> to insure that you'll get the proper value:
- sub validate_passwd {
- my($user,$passwd) = @_;
- my($pwdhash);
- if ( !($pwdhash = (getpwnam($user))[1]) ||
- $pwdhash ne crypt("\U$passwd","\U$name") ) {
- intruder_alert($name);
+ sub validate_passwd {
+ my($user,$passwd) = @_;
+ my($pwdhash);
+ if ( !($pwdhash = (getpwnam($user))[1]) ||
+ $pwdhash ne crypt("\U$passwd","\U$name") ) {
+ intruder_alert($name);
+ }
+ return 1;
}
- return 1;
- }
=item dump
=item waitpid PID,FLAGS
If PID is a subprocess started by a piped C<open()> (see L<open>),
-C<waitpid> will wait for that subprocess, and return its final
-status value in C<$?>. If PID is a subprocess created in some other
-way (e.g. SPAWNed before Perl was invoked), or is not a subprocess
-of the current process, C<waitpid> will attempt to read from the
-process's termination mailbox, making the final status available in
-C<$?> when the process completes. If the process specified by PID
-has no termination mailbox, C<waitpid> will simply check once per
-second whether the process has completed, and return when it has.
-(If PID specifies a process that isn't a subprocess of the current
-process, and you invoked Perl with the C<-w> switch, a warning will
-be issued.)
+C<waitpid> will wait for that subprocess, and return its final status
+value in C<$?>. If PID is a subprocess created in some other way (e.g.
+SPAWNed before Perl was invoked), C<waitpid> will simply check once per
+second whether the process has completed, and return when it has. (If
+PID specifies a process that isn't a subprocess of the current process,
+and you invoked Perl with the C<-w> switch, a warning will be issued.)
Returns PID on success, -1 on error. The FLAGS argument is ignored
in all cases.
by saying
foreach my $key (qw[C-local keys you want promoted]) {
- my $temp = $ENV{$key}; # read from C-local array
- $ENV{$key} = $temp; # and define as logical name
+ my $temp = $ENV{$key}; # read from C-local array
+ $ENV{$key} = $temp; # and define as logical name
}
(You can't just say C<$ENV{$key} = $ENV{$key}>, since the
=head1 Revision date
-This document was last updated on 2-Oct-2001, for Perl 5,
+This document was last updated on 01-May-2002, for Perl 5,
patchlevel 8.
=head1 AUTHOR
-Charles Bailey <bailey@cor.newman.upenn.edu>
-Craig Berry <craigberry@mac.com>
-Dan Sugalski <dan@sidhe.org>
+Charles Bailey bailey@cor.newman.upenn.edu
+Craig Berry craigberry@mac.com
+Dan Sugalski dan@sidhe.org
https://perl5.git.perl.org / perl5.git / blobdiff