 
     SESSION 3.

     The following subjects will be covered in this session:

      string search and replacement
      handling of blocks of text

     Every  word  processing  program has to be able to find  a  given  phrase
within  the edited text.  In this tutorial, the term "string" will be used for
such  a phrase (a small portion of the edited text).  A word has been  defined
in  the  first  session as a sequence of characters delimited by  blanks.    A
string  can  be  a  word (or its fraction) or it can consist of  a  few  words
separated  by blanks. Text buffers in WORDFLEX can be searched for strings  of
up to 70 characters. Strings can be also automatically replaced in one or more
lines of the text buffer.

     The  search  only is performed by invoking the Alt F (for find)  command.
Press Alt F now.  You will be asked whether the entire text is to be searched.
WORDFLEX  expects an affirmative (y or Y) or negative (n or N) answer to  this
and all similarly phrased questions.  You will notice that any other character
is  ignored.  An affirmative answer means that the text will be searched  from
the  beginning.   Negative answer will invoke a search in the portion  of  the
                            ***Press Ctrl Pg Dn***
buffer starting with current line to the end of the text.  Answer y (or Y) and
specify  as  a string the title of this session: SESSION 3.  Almost  instantly
this  screen will be displayed with the title on the first line.  You will  be
then  asked whether a search for the next occurrence of the string is desired.
Answer  y  (Y)  again.  Now one of the lines above will become the  top  line.
Another  affirmative answer will result in the message "String not found"  and
the display will remain unchanged.

     The  replace command is invoked by Alt R and it works very much like  the
Alt  F  command.    You have to specify, however, in addition  to  the  search
string,  the  replacement string.  The found string is again displayed  for  a
brief  period  of  time, than the line turns cyan (high intensity) and  it  is
displayed  again  with the replacement.  You can either accept or reject  that
particular string replacement.

     Try  now the Alt R command on this text, replacing the string Alt R  with
ALT R and back again.

     The  second subject of this session is handling of blocks of text.  Block
of  text  is  defined  as  two  or   more  lines  marked  in  a  special  way.

     Before  we  get  to  the commands for handling these  blocks,  a  special
command that operates on a single line has to be mentioned.  The Alt D command
                            ***Press Ctrl Pg Dn***
 
                                     -2-

deletes    a   line  from  a  buffer irretrievably.  It  is  different from
the  individual    character  deletion invoked by the Del key.   The  Del  key
cannot  be  used  to  erase an entire line of text; it  can  only  delete  all
characters in a line making it a blank line.  Also, the deletion of characters
is    reversible  while  deletion of lines (and blocks of text, as   you  will
see shortly) is  not. Consequently,  caution  has  to  be exercised when using
the Alt  D  command.


     The following special function keys are used to define and access a block
of text:

      F5  -    moves cursor to mark 1 or 2
      F7  -    marks an unmarked line or unmarks a marked line
      F8  -    erases marks

     Only  one  text block can be marked in WORDFLEX at a time.  The block  is
delimited  by two marked lines (they are part of the block).  Line marked as 2
has  to  follow line marked as 1 in the text and both marked lines have to  be
in the same buffer.
                            ***Press Ctrl Pg Dn***
     The following commands are used to manipulate blocks of text:

      Alt C    -    inserts block of text after the current line and leaves
                    the original block intact

      Alt E    -    erases block of text irretrievably

      Alt M    -    inserts block of text after the current line and
                    removes if from its original location

     The  important  feature of the Alt C and Alt M command is that it  allows
transfer of blocks of text between two separate buffers.  When such a transfer
is  invoked, a confirmation is requested.  If approved, the copying or  moving
operation  proceeds, thus allowing the pasting together of text from different
file buffers.

     If the marked line is not a blank line, it is displayed in reversed video
for  an emphasis.  Whether this display attribute is in effect or not, the  F5
command  will always move the cursor to the selected mark.  The Alt S  command
provides information about the status of the marks.

     Now  load  a text file (perhaps your own file test.txt) on the  next  two
buffers  and  practice the line deletion, marking and manipulation of  blocks.
                            ***Press Ctrl Pg Dn***
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                                     -3-

Unlike  the  commands described in Session 2, all block manipulation  commands
are  irreversible.    It is, of course, always possible to move a  block  back
where it came from or erase a copied block that was marked incorrectly.  It is
not possible, however, to recover from an erasure of a block of text.  This is
one  of the reasons why a periodic storage of the text buffer on a file should
be  performed  during  a  lengthy  editing session.  Even  in  a  case  of  an
inadvertent error, the loss of text can be thus minimized.

     This concludes the third WORDFLEX tutorial session.
