page

Command: page


Description

The "page" command is used by NEST's online-help system to display
the help pages. It displays the contents of a file either through a
built-in pager or an external pager program. The text you are
reading right now is displayed using "page".

You can customize the display. Type "/page ShowOptions" to show your
current settings. Use the "SetOptions" command to customize the
pager program. Here are some useful suggestions. You will want to
put your favourite into your ~/.nestrc file (see "/nestrc help"):

1. /page << /command (more) % Use more as a pager
/wait true >> SetOptions % and wait for termination

2. /page << /command (less -S) % Use less as a pager
/wait true >> SetOptions % and wait for termination

3. /page << /command (xterm -e less -S) % Run less in a separate xterm window...
/wait false >> SetOptions % ..so we can go on working in parallel.

4. /page << /command (xless) % Use xless as a pager
/wait false >> SetOptions % xless opens it's own window.

5. /page << /command (xemacs) % If you like to show helpfiles using xemacs.
/wait false >> SetOptions % xemacs opens it's own window.

6. /page << /command false >> SetOptions % use built-in pager.

7. /page ResetOptions % Return to the default configuration ($PAGER or built-in pager).

Author
R Kupper

Bugs
The string contained in /command is processed by "breakup" to separate
the command from its parameters. Be aware that there is a bug in the
"breakup"-routine which makes it impossible to pass a parameter
containing blanks by enclosing it in quotation marks.

WARNING: Setting the /wait option to false with a pager
program that writes to stdout will screw up your SLI prompt.

Synopsis
(filename) page -> -

Examples

The following example displays the license agreement that came with
your copy of NEST:

"statusdict /prgdatadir get (/LICENSE) join page"

File
lib/sli/helpinit.sli
Remarks
If /wait is set to false the "system"-command is called in
no-care-mode. Be aware that this may be an expensive operation
depending on the ressources your SLI-process occupies.
(see description of "system").
Even if /wait is set to true creation of a child process may
be expensive. To avoid any overhead caused by process creation set /command
to false.

FirstVersion
Apr 22 1999 reworked 27-sep-2007

Options

/command - UNIX command to display a file (default: see below)

/command can be either false or a string.
If /command is set to false "page" uses the simple built-in
pager "ppage" for display.

If it is set to the name of a UNIX program "page" will execute
this program as a child process passing the name of the
file as argument.

/command defaults to the contents of the $PAGER environment
variable. If this variable is not set it defaults to false.

/wait - whether to wait for the UNIX program to finish. (default: true)

If /wait is set to true the "page" command will not return until
the UNIX process is terminated. Use this setting for all pager
programs that write to stdout.

If /wait is set to false "page" will return immediately after
creating the child process. Use this setting for all pager programs
that open up their own window.

The value of /wait is ignored if /command is set to false.