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tutorials:edit

EDIT is a line-oriented text editor for TOPS-20 on TWENEX.ORG.

Invocation

EDIT is usually started with the EDIT command. However, if you have customized your default editor, the EDIT command may invoke a different editor. To run EDIT without disturbing your default editor setting, use the command SYS:EDIT or R EDIT.

Command Line Editing

As a line-oriented editor, all editing tasks are accomplished in EDIT by entering commands at the EDIT command prompt (*). If you wish to make changes to the current command line before submitting it (by pressing Enter), you may use the following keys:

  • Delete (usually mapped to the Back Space key) – Delete one character to the left of the cursor.
  • Ctrl-U – Delete the entire command line without submitting it.

Basic Commands

  • Da[:b] – Delete line a (through line b).
  • E – Save file and return to EXEC.
  • EQ – Discard unsaved changes and return to EXEC.
  • Ia – Insert mode after line a. End with Esc key.
  • Pa[:b] – Print line a (through line b) on terminal.
  • Ra – Replace line a
  • StEscuEsca – Substitute text u for text t on line a.

More Commands

TWENEX's on-line help file for EDIT is reproduced below.

Summary of EDIT commands        10-Feb-76

I    Insert              [<position>,<increment>]
P    Print               [<range>][,N]
.    Move pointer        [<position>]
D    Delete              [<range>]
K    Kill page mark      [/<page number>]
R    Replace             [<range>,<increment>]
E    End (Exit to command level)
 EN  Suppress ".Qxx/.Zxx" file creation
 EI  Insert identifying line before ending
 EJ  Delete first line of file and do an EI command
 EQ  Quit (while you're ahead)
 EU  Unsequence output file
G    Go (Exit and do last LOAD-class command)
 GI  Do an EI command, and then go
 GJ  Do an EJ command, and then go
 GN  Do an EN command, and then go
 GU  Do an EU command, and then go
B    Backup - (same as E but leaves you at EDIT command level)
 BI  Do an EI command, without ending
 BJ  Do an EJ command, without ending
 BN  Do an EN command, without ending
 BU  Do an EU command, without ending
M    Mark                [<position>]
N    Number              [<increment>,<range>,<start>]
 NA  Add <increment> to <range>
 NP  Preserve line numbers over page marks
L    List (on LPT)       [<range>]
J    Join                [<position>]
F    Find                [<string>$<range>,<foptions>]
S    Substitute          [<old string>$<new string>$<range>,<soptions>]
C    Copy                [<dest-position>,<range>]
        or               [<dest-position>=<filespec>,<range>]
        or               [<dest-position>=<filespec>/S]
T    Transfer            [<dest-position>,<range>]
X    eXtend              [<range>,L] (,L suppresses typeout)
H    Help (types this text)
?    Types list of available commands
<LF> Same as P.+1
$    Same as P.-1
@<filespec>      Indirect command file

A    Alter               [<range>]

    ?          Print list of alter commands
   nC<ch>      Change n characters
  -nD          Delete next/last characters
    E          Finish with no printing
  -nF<ch>      Find the nth next/previous occurrence of <ch>
   nI<text>$   Insert with temp increment n
    J          Break line and stick rest at front of next
  -nK<ch>      Delete to n occurrences of <ch>
    L          Print line and recycle
    P          Print line and recycle to current position
    Q          Quit ALTER (restore original line)
  -nR<text>$   nD then 0I
   nW          Skip forward n words
    X<text>$   Delete word then 0I
  -n<SP>       Space forward/backward n characters
    <CR>       Finish and print rest of line
   n<RUB>      Backspace n characters
   n<BS>       Backspace n characters
   -<HT>       Skip to end/start of line
    ^U         Quit and restart ALTER

EDIT parameters:*

name         set  print  default value          what

  .           n     y       ---            current <position>
  ?           n     y       ---            /? list settable switches
                                           =? list printable switches
BAK           y     y       on             create backup file <.Qxx>
BIG           n     y       ---            largest page #
C64           y     CASE    on             64 character set
C128          y     CASE    off            128 character set
CASE          n     CASE    C64 M33 UPPER  give case information
DECIDE        y     y       off            auto ",D" for "S" command
DPY           y     n       off            special  display mode
ERROR         n     y       ---            print last error message
EXPERT        y     n       off            Q.E.D
INCREMENT     y     y       100            default line increment
INSERT        y     n       ---            location of next I<CR>
ISAVE         y     y       0              controls auto-W on inserts
LOCATION      n     y       ---            first line in edit buffer
LOWER         y     CASE    off            default lower case
M33           y     CASE    on             terminal characteristics
M37           y     CASE    off            terminal characteristics
NAME          y     y       ---            output file spec
NOBAK         y     n       off            no backup file
NODECIDE      y     n       on             no auto ",D"
NONSEPARATORS y     CASE    on             %,$,. are not alphanumerics
NONUMBER      y     n       off            don't print line numbers
NOVICE        y     n       on             normal mode
NUMBER        y     n       on             print line numbers on
                                           terminal
OLD           y     n       off            creat backup file (.Zxx)
OPTION        y     n       ---            read "SWITCH.INI" file
PLINES        y     y       16             used by "P<CR>
R             Same as RONLY
RONLY         y     n       off            read-only file
READONLY      Same as RONLY
RUN           y     y       LOAD-class     set run spec
SAVE          y     y       0              controls auto-W on commands
SEPARATORS    y     n       off            treat %,$,. as alphanumeric
START         y     y       100            starting sequence #
STEP          y     y       100            default line increment
STRING        n     y       ---            current F & S strings
UNSEQUENCE    y     n       off            unsequence output file
UPPER         y     CASE    on             default upper case
WINDOW        y     y       8              size of edit file window

   * All settable parameters may be specified as switches in the
initial command string.

EDIT special characters:

Replacement:   ^B  '"    next match string
               ^O  '*    '*<number>'* is nth match string
               ^^  '7    quote next character

Match:         ^E  '%    not
               ^N  ')    arbitrary number of
               ^T  '/    any character
               ^^  '7    quote next character
                ^  ':    separator

Positions:     .    present line or page
               ^    first line or page
               *    last line or page

EDIT definitions and meanings:

<range>    ::= <pos>[!<number> or
                     :<pos>]

<pos>      ::= [<line>][/<page>]

<line>     ::= [<number> or
                <content> or
                . or * or ^][(+-)<number>]

<page>     ::= [<number> or
                . or * or ^][(+-)<number>]

<content>  ::= $<string>$<range>,<foptions>

<number>   ::= any positive integer .LE. 2^35-1

Options:

     ,D   Decide on each substitution (S command)
     ,E   Match upper/lower case characters Exactly (F and S commands)
     ,L   Do not print contents of line (F, S, and X commands)
     ,A   Enter ALTER mode (F and S commands)
     ,N   Do not print line number (P command)

Special functions of the "I" command:

I<CR>       default is set to end of last:
               Replace, except at end of page
               Insert, except wrap around or out of space

I/<page>    does insert page mark at end of <page> followed by Istart,
            where start is the value of the START switch (Originally,
            the START switch is set at 100).

I<pos>!n    allows insertion of n lines; calculates increment from
            table of aesthetic values.

I^          inserts a line at the top of the page, halfway between line
            0 and the first line.

EDIT  Command Format:

@CREATE (FILE) /switches input.typ.gen
or,
@EDIT (FILE) /switches input.typ.gen (OUTPUT AS) output.typ.gen

CREATE requires that input.typ.gen is a new file; EDIT
works regardless of whether the file exists or not.

/switches  is a list of settable switches which may
be recognized.  If an illegal switch is encountered,
the entire command is ignored.

input.typ.gen, and output.typ.gen are TOPS-20 file
specifications; recognition is available.  Output.typ.gen
defaults to input.typ.-1 if it is not explicitly typed.

References

  • (EDIT User's Guide and EDIT Reference Manual were published by DEC as part of the TOPS-20 Software Notebook series, but the author has been unable to locate any printed or electronic copies of either manual.)
tutorials/edit.txt · Last modified: 2016/10/20 03:44 by papa