!TITLE VIEWing a File                 
!
!
!
!     The little message '...more' at the bottom means that
!     there is more in this section!
!
!     You get to the next page by pressing the 'return' key.
!
!     (You always have to press the 'return' key to make VIEW
!     do something)
!
!PAGE
!     When VIEW displays a continuation page, like this one, it
!     puts the continuation number (in this case 2) in the top
!     right hand corner.
!
!
!     You can go to continuation page n in a section by typing
!     /n
!
!     / by itself takes you to the last page of the section
!
!
!     As an example, type /3 and then press the 'return' key
!     to get to the next page in this section
!PAGE
!
!
!
!
!     You can go straight to continuation page n in a section by typing
!     /n after the section number.
!
!
!
!     For example, type 1/4 to get to the next page.
!PAGE
!
!
!     Sometimes it is more convenient to refer to a section
!     by its name rather than its number. You can do this by
!     typing its name or, even, just part of its name.
!     The note below says how this is done more precisely.
!
!
!     For example, type VIEWING/5 and press the 'return'
!     key to get to the next page.
!
!
!Note:
!VIEW scans the full contents looking first for an exact match.
!If there is more than one, it replies 'non-unique'. If there is only
!one exact match, it displays that section. If there are no exact
!matches, it scans the full contents again looking for a matching
!substring. If there is more than one, it displays a list of all those
!found. If there is only one, it displays that section. Otherwise, it
!replies 'no match found'.
!
!
!
!     When VIEW displays a section, it first displays the preface
!     and then gives the names of the subsections at the next level.
!
!     You can get a list of these names, and of the names of all
!     the sub-subsections etc by typing C
!
!
!     If you do this now, you will have to type 1/5 to get back
!     here.
!PAGE
!     If you wish to look at subsection n of the current section,
!     it is sufficient to type in .n
!
!
!     Thus if you are looking at 2.1 and you type in .1, you will go
!     to 2.1.1
!
!
!     For example, type .1 to look at subsection 1.1
!PAGE
!
!     To exit from VIEW, type
!           Q (or QUIT, E, END or STOP) 
!
!     When you have found your way around section 1, do
!     have a look at the following.
!
!<Getting Back !
!KEY
!
!     If you are eg in section 2.1.1 and wish to get back to 2.1,
!     you can of course type 2.1
!
!     Alternatively, you can type U which will take you back up
!     one level. You can get right back to the top of the file
!     by typing T.
!
!     If you type U/ now, you will go to the end of 1
!>
!<Extracting material
!
!     You can extract material from the file you are VIEWing by typing
!
!           F<filename>             eg F<FRED>                    
!     or    F<output device>        eg F<.LP>
!
!     All the text of the current section and any sub-sections is
!     output. However, if you are VIEWing the 'contents' of a section, 
!     a list of contents is output rather than the text.
!
!     The <filename> may be that of an ordinary file or a member of
!     (a member of) a PD file.
!
!     An existing file will be overwritten only if you write
!     F<filename/W). You can append a section to a file by writing
!     F<filename-MOD>
!
!     You can use F<.OUT> to output a section to your terminal,
!     a convenient way to get a copy of a short section.
!PAGE
!     The F command outputs the material without any regard to how it
!     appears on the screen. If you wish to preserve the screen
!     format, use the command
!
!           X<filename>
!
!     This lists each screenful in the current section and any
!     subsections to the specified file. Each screenful consists of:
!
!           - a marker:        !section number/frame number
!           - the section name and number
!           - a row of minus signs
!           - 20 lines of information
!
!     If you are VIEWing the 'contents' of a section, a list of
!     contents is output. In this case the marker is
!
!           !Csection number/frame number
!>
!<Alphabetic Search
!   If you are looking at a section which has one or more subsections,
!   but no subsubsections, and the names of the subsections are in
!   alphabetical order, and you type
!
!               name?
!
!   View will display the subsection with the 'greatest' name 'less
!   than' the one you gave.
!
!   If you give another alphabetic search command and the section you
!   are currently viewing is not suitably structured, then the previous
!   correctly structured section is scanned.
!>
!<Bookmarks
!   The bookmark facility allows you to remember where you are in a
!   file, look at another part of it and then return to where you were.
!   Several bookmarks can be set and you return to the most recently 
!   inserted.
!
!               B
!
!   sets a bookmark and
!
!               R
!
!   returns to the most recent bookmark and discards it. If there are
!   no bookmarks set, R returns to the 'basefile', see the next section.
!>
!<Subsidiary Files
!
!     A powerful feature of VIEW is that the file you are viewing, the
!     basefile, can reference subsidiary files. These appear as sub-
!     sections of the basefile but are distinguished from ordinary
!     sub-sections in the contents by an asterisk. You examine a sub-
!     file by specifying its section number or name in the usual way.
!
!     When you 'get into' the subsidiary file, it has its own section
!     numbers starting from 1 just like the basefile.
!
!     You get out of a subsidiary file and return to the basefile by
!     typing R
!
!     You can go down several levels in this way, each subsidiary
!     file serving as the basefile for the next level.
!PAGE
!     The command
!
!           V filename
!
!     allows you to view another file and then, by using R, return to
!     the current file.
!
!     You can determine the structure of a file in terms of its
!     subsidiary files with the S (=structure) command.
!
!     A related command is W (Where am I?) which lists the names of
!     the files you have traversed to reach the current position.
!>
!<Titles and Topics
!     The name of a file is not always a convenient way of referring
!     to it. As an alternative, the author of a file can specify a
!     'title' (up to 31 characters). For example, this file has a
!     title of 'How to use VIEW'.   By default, the title is the name
!     of the file.
!
!     Sometimes a short identifier for a file is required. This is
!     provided by the 'topic', the default once again being the name
!     of the file.
!>
!<Keys
!     Each VIEW file has a 'key' directory which contains keys and
!     section numbers. By default, the keys for a section are
!     derived from its title but an author can nominate alternative
!     keys or suppress all keys for a section. The key directory
!     is used in the command
!
!           K<mask>
!
!     The conventions for mask are the same as those for the FILES
!     command, namely:
!           ABC       selects key ABC
!           ABC*      selects keys starting with ABC
!          *ABC       selects keys ending with ABC
!          *ABC*      selects keys containing ABC
!     If only a single section is found or, if only one section is
!     found whose name is exactly equal to the mask, that section is
!     displayed. Otherwise, up to 18 references are displayed
!     numbered 1, 2, 3... To view one of these references it is
!     sufficient to type in its number. To return to the 'basefile'
!     after viewing a reference, R is used in the usual way.
!PAGE
!     After a successful search, the resulting action (display a
!     single section or give list) can be invoked again by giving
!     the command K with no parameter.
!
!     The search can be made more specific by giving additional masks
!     separated by & eg
!
!           K<FILE&CONN*>
!
!     The search can be extended to all the subsidiary files by
!     terminating the mask with + eg
!
!           K<FILE&CONN*+>
!
!     If no references are found and mask does not contain any
!     asterisks, the search is repeated with asterisks appended.
!>
!<Calling VIEW
!
!     When you call VIEW, you may specify the name of a PD file and a
!     sequence of VIEW commands separated by commas. If the filename is
!     omitted, SUBSYS.VIEWBASE is viewed. If the command sequence is
!     omitted, you view the first page of the file. eg
!
!           VIEW                 views the first page of SUBSYS.VIEWBASE
!           VIEW(MYFILE,S)       gives the structure of MYFILE
!
!     When you are in VIEW, you can give several commands on one line
!     separated by commas.
!>
!<EMAS commands
!     You can obey an EMAS command from within VIEW by typing
!
!           #command
!or
!           #command parameters-separated-by-commas
!
!     on a single line by itself.
!>
!<Killing Output
!     If you have asked VIEW to do the 'wrong' thing and now wish to
!     discard any output and return to the View: prompt immediately,
!     you may do
!
!           Int:K
!>
!>