IO::Pager(3) User Contributed Perl Documentation IO::Pager(3)NAME
IO::Pager - Select a pager, optionally pipe it output if destination is
a TTY
SYNOPSIS
#Select a pager, sets $ENV{PAGER}
use IO::Pager;
#Optionally pipe output
{
#local $STDOUT = IO::Pager::open *STDOUT;
local $STDOUT = new IO::Pager *STDOUT;
print <<" HEREDOC" ;
...
A bunch of text later
HEREDOC
}
DESCRIPTION
IO::Pager is lightweight and can be used to locate an available pager
and set $ENV{PAGER} (see "NOTES") or as a factory for creating objects
defined elsewhere such as IO::Pager::Buffered and
IO::Pager::Unbuffered.
IO::Pager subclasses are designed to programmatically decide whether or
not to pipe a filehandle's output to a program specified in
$ENV{PAGER}. Subclasses are only required to support filehandle output
methods and close, namely
CLOSE
Supports close() of the filehandle.
PRINT
Supports print() to the filehandle.
PRINTF
Supports printf() to the filehandle.
WRITE
Supports syswrite() to the filehandle.
For anything else, YMMV.
new( [FILEHANDLE], [EXPR] )
Instantiate a new IO::Pager to paginate FILEHANDLE if necessary.
Assign the return value to a scoped variable.
See the appropriate subclass for implementation specific details.
FILEHANDLE
Defaults to currently select()-ed FILEHANDLE.
EXPR
An expression which evaluates to the subclass of object to create.
Defaults to IO::Pager::Unbuffered.
open( [FILEHANDLE], [EXPR] )
An alias for new.
close( FILEHANDLE )
Explicitly close the filehandle, this stops any redirection of output
on FILEHANDLE that may have been warranted. Normally you'd just wait
for the object to pass out of scope.
This does not default to the current filehandle.
See the appropriate subclass for implementation specific details.
ENVIRONMENT
PAGER
The location of the default pager.
PATH
If PAGER does not specify an absolute path for the binary PATH may
be used.
See "NOTES" for more information.
FILES
IO::Pager may fall back to these binaries in order if $ENV{PAGER} is
not executable.
/usr/local/bin/less
/usr/bin/less
/usr/bin/more
See "NOTES" for more information.
NOTES
The algorythm for determining which pager is to use as follows:
1. Defer to $ENV{PAGER}
Use the value of $ENV{PAGER} if it exists unless File::Which is
available and the pager in $ENV{PAGER} is determined to be
unavailable.
2. Usual suspects
Try the standard, hardcoded paths in "FILES".
3. File::Which
If File::Which is available check for "less" and more.
4. more
Set $ENV{PAGER} to "more"
Steps 1, 3 and 4 rely upon $ENV{PATH}.
SEE ALSO
IO::Pager::Buffered, IO::Pager::Unbuffered, IO::Pager::Page
IO::Page, Tool::Less
AUTHOR
Jerrad Pierce <jpierce@cpan.org>
This module is forked from IO::Page 0.02 by Monte Mitzelfelt
LICENSE
· Thou shalt not claim ownership of unmodified materials.
· Thou shalt not claim whole ownership of modified materials.
· Thou shalt grant the indemnity of the provider of materials.
· Thou shalt use and dispense freely without other restrictions.
perl v5.12.5 2005-09-21 IO::Pager(3)
