File viewer with syntax highlighting, written in x86_64 Linux assembly. No libc, no runtime, pure syscalls. Single static binary, 38KB.
A less/cat/bat replacement. Three modes: full-screen pager, cat-style output, and embeddable pane output for TUI applications.
git clone https://github.com/isene/show.git
cd show
make
sudo make installshow follows a file that other processes rewrite. Leave it open on a log,
a generated report or a file you are editing in another window, and the view
updates as the file changes.
- Written in place, or replaced atomically (write temp, rename over): both are picked up. The second is what vim, scribe and the CHasm config tools do, and it orphans a naive watch, so the watch re-arms on the path.
- Parked at the bottom, it stays at the bottom, so a growing file follows
like
tail -f. Anywhere else, your position is kept. - Costs nothing when nothing happens: an inotify fd joins the keyboard in a
single blocking
poll, so an idle pager makes no wakeups at all. The watch is on the file itself, not its directory, so a busy directory full of other files never interrupts it. - Piped input (
cmd | show) has no file to follow and is unchanged.
show /var/log/syslog # then press GG parks you at the end, and from there every append scrolls into view,
with syntax colours and the pager's search and navigation still available.
Press g (or scroll up) to stop following and read back through the file:
appends keep arriving, but the view stays where you put it. G again to
resume following.
Unlike tail -f this costs nothing while the file is quiet, and unlike
less +F you are never locked out of the pager: the keyboard stays live
the whole time.
show file.rb # full-screen pager (if stdout is a terminal)
show file.py | grep def # cat mode with colors (if stdout is a pipe)
echo "hello" | show # pipe mode (reads stdin, pages like less)
show --lines 10-30 file.c # pane mode (for embedding in TUI apps)
show /var/log/syslog # live view; press G to follow it like tail -f
| Key | Action |
|---|---|
| j / Down | Scroll down one line |
| k / Up | Scroll up one line |
| Space / PgDn | Page down |
| b / PgUp | Page up |
| g / Home | Go to top |
| G / End | Go to bottom |
| l | Toggle line numbers |
| Left / Right | Horizontal scroll |
| / | Search forward (Enter runs it, Esc cancels) |
| n | Jump to the next match |
| N | Jump to the previous match |
| q | Quit |
Every match on a visible line is shown in reverse video, so you can see which word was hit and how many times.
Search wraps at either end of the file, and follows vim's smartcase
rule: an all-lower-case pattern ignores case, a pattern with any
capital in it matches exactly. A pattern that matches nothing says
pattern not found in the status bar and leaves the view where it is.
20+ languages with keyword, type, function, string, comment, number, and operator coloring:
| Language | Extensions |
|---|---|
| Assembly | .asm, .s |
| C/C++ | .c, .h, .cpp, .hpp, .cc |
| C# | .cs |
| Forth | .fth, .4th, .forth |
| Go | .go |
| Java | .java |
| JavaScript/TypeScript | .js, .ts, .jsx, .tsx |
| Julia | .jl |
| Lua | .lua |
| Python | .py |
| Ruby | .rb, .gemspec |
| Rust | .rs |
| Shell | .sh, .bash, .zsh, .fish |
| XRPN | .xrpn |
| JSON | .json |
| YAML | .yaml, .yml |
| TOML | .toml |
| Markdown | .md |
| Config | .conf, .cfg, .ini |
Shebang detection: files without extensions are identified by #!/...ruby, #!/...python, etc.
| Element | Color |
|---|---|
| Keywords | Hot pink (197) |
| Strings | Green (78) |
| Comments | Gray (242) |
| Numbers | Purple (141) |
| Types | Cyan (81) |
| Functions | Yellow-green (148) |
| Operators | Light gray (248) |
| Line numbers | Dark gray (240) |
Colors match the pointer file manager's built-in highlighter.
Pager mode (default when stdout is a terminal): full-screen with scrolling, status bar, and line numbers. Uses alternate screen buffer.
Cat mode (when stdout is a pipe): outputs all lines with syntax highlighting and line numbers. Works like bat or cat with colors.
Piped input (cmd | show): stdin is slurped, then show reopens /dev/tty for the keyboard and runs the full pager — the same trick less uses. If stdout is also piped (or there is no controlling terminal), it falls back to cat mode.
Pane mode (--lines M-N): outputs a specific line range with highlighting. No raw mode, no key handling. Designed for embedding in TUI applications like pointer and RTFM.
Part of CHasm (CHange to ASM)
| Tool | Purpose | Binary |
|---|---|---|
| show | File viewer | 40KB |
| bare | Interactive shell | 150KB |
| glass | Terminal emulator | 110KB |
| tile | Window manager + strip status bar | 70KB |
| chasm-bits | Status-bar asmites | ~5KB each |
| glyph | TrueType rasterizer | 37KB |
Unlicense - public domain.
Created by Geir Isene (https://isene.org) with pair-programming with Claude Code.