notispf

A text editor inspired by the ISPF editor from z/OS mainframes, available as both a terminal app and a desktop GUI. Brings the prefix command area that ISPF users know and love to Linux, macOS, and Windows.

Installation

Download (no Python required)

Go to the Releases page and download for your platform:

Platform	GUI (recommended)	Terminal CLI
Linux	notispf-qt-x86_64.AppImage	notispf-linux
macOS	notispf-qt.dmg	notispf-macos
Windows	notispf-qt-setup.exe	notispf-windows.exe

Linux AppImage:

chmod +x notispf-qt-x86_64.AppImage
./notispf-qt-x86_64.AppImage myfile.txt

macOS DMG: Open the .dmg and drag notispf-qt to your Applications folder.

macOS note: Without code signing, Gatekeeper will block the app on first launch. Right-click the app → Open → Open to bypass the warning once. For the CLI binary: xattr -d com.apple.quarantine ./notispf-macos

Windows installer: Run notispf-qt-setup.exe. Creates a Start Menu entry and an optional desktop shortcut.

Windows note: SmartScreen may warn about an unknown publisher. Click More info → Run anyway.

Linux / macOS CLI:

chmod +x notispf-linux   # or notispf-macos
./notispf-linux myfile.txt
mv notispf-linux ~/.local/bin/notispf   # optionally add to PATH

Via pip

pip install notispf           # terminal version
pip install notispf[qt]       # terminal + GUI (requires PyQt6)

From source

git clone https://github.com/mrthock/notispf
cd notispf
pip install -e .          # terminal version
pip install -e ".[qt]"    # terminal + GUI

Usage

GUI (PyQt6):

notispf-qt <file>
notispf-qt           # opens a file picker dialog

Terminal:

notispf <file>

Screen Layout

 notispf  filename.txt                    Line 1/42  Col 1
===> _
000001|This is the first line of your file
000002|Second line here
000003|Third line
      |~
      |~
F1-HELP  F3-SAVE  F5-RFIND  F6-CMD  F7-UP  F8-DOWN  F10-LEFT  F11-RIGHT  F12-QUIT
                                                                 [message bar]

• Status bar (top row) — filename, modified flag [+], current line/total, cursor column, [HEX] when hex mode is active
• Command bar (second row) — always visible; type commands here after pressing F6 to focus it
• Prefix column (left, 6 chars) — shows zero-padded line numbers; type prefix commands here
• Text area (right of |) — edit your file
• Function key bar (second-to-last row) — always-visible reference for function key shortcuts
• Message bar (bottom row) — status messages and feedback

Navigation

Key	Action
Arrow keys	Move cursor in text
Up (from top visible line)	Move to command bar
Page Up / Page Down	Scroll
Home	Focus command bar
Ctrl+A	Beginning of line
End / Ctrl+E	End of line

Switching Between Areas

From	Key	To
Text	Home	Command bar
Text	Tab	Prefix column of next line (N+1)
Text (col 0)	Left arrow	Prefix column of same line
Text (top line)	Shift+Tab	Command bar
Text (any other line)	Shift+Tab	Prefix column of previous line (N-1)
Prefix	Right arrow	Text area of same line (col 0)
Prefix	Home	Command bar
Prefix	Tab	Text area of same line
Prefix	Shift+Tab	Text area of previous line (N-1)
Command bar	Tab	Prefix area of line 1
Command bar	Down arrow	Text area (cursor position preserved)
Command bar	Escape	Text area (cursor position preserved, bar stays visible)

Prefix Commands

Type a command into the prefix column, then press Enter to execute. You can stage commands on multiple lines before pressing Enter — they all execute at once.

Single-Line Commands

Command	Action
D	Delete line
Dn	Delete n lines (e.g. D5 deletes 5)
I	Insert blank line after
In	Insert n blank lines
R	Repeat line
Rn	Repeat line n times
C	Copy line to clipboard
Cn	Copy n lines to clipboard
M	Move line (cut to clipboard)
Mn	Move n lines
A	Paste clipboard after this line
B	Paste clipboard before this line
O	Overlay clipboard onto this line (merge; clipboard spaces don't overwrite)
On	Overlay clipboard onto n lines
>n	Indent right n columns (e.g. >4 adds 4 spaces)
<n	Indent left n columns (removes up to n leading spaces)
HEX	Replace this line with its hex representation
HEXB	Insert a hex copy of this line below it
HEXA	Convert a hex line back to ASCII text
UC	Uppercase this line
UCn	Uppercase n lines (e.g. UC3)
LC	Lowercase this line
LCn	Lowercase n lines

Block Commands

Type the command on the first line of the block, then again on the last line.

Command	Action
DD	Delete block
CC	Copy block to clipboard
MM	Move block (cut to clipboard)
RR	Repeat block (insert a copy below)
OO	Overlay clipboard onto block (merge clipboard text into block lines)
>>n	Indent block right n columns
<<n	Indent block left n columns

Use A, B, or O/OO on a third line to place the clipboard after copying or moving.

Example — move lines 3–6 to after line 10:

1. Tab to line 3 prefix → type MM
2. Arrow down to line 6 → type MM
3. Arrow down to line 10 → type A
4. Press Enter

Exclude / Show Commands

Command	Action
X	Exclude line from display (collapse into fold row)
Xn	Exclude n lines
S	Show (un-exclude) line or the entire fold group it belongs to
Sn	Show n lines
XX	Exclude block
SS	Show block

Excluded lines are collapsed into a single fold row showing the count. Use SHOW ALL on the command line to reveal everything at once.

Prefix Mode Controls

Key	Action
Enter	Execute all staged prefix commands
Escape	Cancel all staged commands and exit prefix mode
↑ / ↓	Move between lines (keeps staged commands)

Command Line

The command bar is always visible just below the status bar. Press F6 to focus it (the cursor moves to ===>), type a command, and press Enter to execute. After the command runs the input clears, the result appears in the message bar, and the cursor stays at ===> ready for another command. Press Escape or Down arrow to return to the text. Press F6 again while focused to hide the bar entirely; press F6 once more to bring it back.

File Commands

Command	Action
SAVE	Save file
FILE	Save and exit
CANCEL or QUIT or CAN	Exit without saving

Copy File

Command	Action
COPY filename	Save a copy of the current file to filename (current file path unchanged)

Undo / Redo

Command	Action
UNDO	Undo last change
REDO	Redo last undone change

Hex Mode

Command	Action
HEX ON	Convert entire file to hex (e.g. Hello → 48 65 6C 6C 6F)
HEX OFF	Convert hex back to text

[HEX] appears in the status bar while hex mode is active. HEX ON and HEX OFF each count as a single undo step.

Exclude and Delete

EXCLUDE 'pattern'
EXCLUDE 'pattern' ALL
EXCLUDE 'pattern' n

DELETE 'pattern'
DELETE 'pattern' ALL
DELETE 'pattern' n
DELETE X ALL
DELETE NX ALL

• EXCLUDE 'pattern' — exclude the next matching line from display
• EXCLUDE 'pattern' ALL — exclude all matching lines
• EXCLUDE 'pattern' n — exclude the next n matching lines
• DELETE 'pattern' — delete the next matching line
• DELETE 'pattern' ALL — delete all matching lines
• DELETE X ALL — delete all currently excluded lines
• DELETE NX ALL — delete all non-excluded lines

Show

Command	Action
SHOW ALL	Reveal all excluded lines

Display

Command	Action
COLS	Toggle the column ruler on/off
CLEAR / RESET / RES	Clear the current search highlight
HELP	Open the help screen

Find and Change

FIND 'text'
CHANGE 'old' 'new'
CHANGE 'old' 'new' ALL
CHANGE 'old' 'new' ALL .labelA .labelB

Both single and double quotes are accepted as delimiters.

Aliases: F for FIND, C for CHANGE, CAN for CANCEL, RESET/RES for CLEAR.

• FIND — locate next occurrence (case-insensitive by default)
• CHANGE — replace next occurrence
• CHANGE ... ALL — replace all occurrences in file
• CHANGE ... ALL .A .B — replace all occurrences between labeled lines

Labels

Type .A, .B etc. in the prefix column to assign a label to a line. Labels are used to define ranges for CHANGE ... ALL .A .B.

Function Keys

Key	Action
F1	Help
F3	Save and exit
F5	Repeat last FIND (RFIND)
F6	Focus command bar (or hide it if already focused)
F7 / Page Up	Scroll up
F8 / Page Down	Scroll down
F10	Scroll left
F11	Scroll right
F12	Exit without saving
Ctrl+Z	Undo last change
Ctrl+Y	Redo last undone change

Contributing

notispf is designed to be easy to extend. Adding a new prefix command takes three steps:

1. Write a handler function in notispf/commands/line_cmds.py:

def cmd_trim(buffer: Buffer, line_idx: int, count: int) -> EditorResult:
    for i in range(line_idx, min(line_idx + count, len(buffer))):
        buffer.replace_line(i, buffer.lines[i].text.rstrip())
    return EditorResult(success=True)

2. Register it in the same file's register() function:

registry.register_line_cmd(CommandSpec("T", cmd_trim, description="Trim trailing whitespace"))

3. Add tests in tests/test_line_cmds.py.

That's it — no changes to the prefix state machine, display, or app controller needed.

See ARCHITECTURE.md for a deeper overview of the codebase.

License

MIT