Stream Editor

Run a safe ed/sed-style command script over pasted text locally. Substitute, delete, print, insert, append, change, branch, and address by line number or regex without shell access.

Run sed-style edits without a shell

Stream Editor applies a small sed/ed-style command script to pasted text entirely in the browser. It uses sed's familiar cycle model: each input line becomes the pattern space, matching commands run in order, and the line is printed automatically unless Quiet mode is enabled.

Common scripts work as expected:

s/foo/bar/g — substitute every foo with bar on each line.
/^$/d — delete blank lines.
2,5d — delete lines 2 through 5.
/error/p with Quiet mode — print only matching lines.
1i header, $a footer, and /old/c replacement — insert, append, or change text.

Filesystem and shell sed commands are deliberately unavailable in the sandbox. Commands such as reading a file, writing a file, or executing a shell command return a clear error instead of reaching outside the pasted text.

Worked example

Input:

foo

keep foo
drop this

Script:

s/foo/bar/g
/drop/d
/^[[:space:]]*$/d

Output:

bar
keep bar

The first command replaces foo, the second deletes any line containing drop, and the third removes blank lines.

Limits and edge cases

Output is capped by Max output lines (default 100,000) to stop accidental explosions.
A separate step cap stops runaway branch loops.
Basic regex mode follows sed/BRE-style escaping. Choose Extended for sed -E style groups and alternation.
Whole buffer mode loads the whole input into one pattern space for multi-line edits; most line-by-line scripts should leave it off.
CRLF output is available for Windows-oriented text, but input line endings are normalized before editing.

FAQ

Is this a full GNU sed clone?

No. It implements the common stream-editing core for pasted text: addresses, ranges, substitutions, delete, print, insert/append/change, transliteration, hold space, labels and branches. Commands that require a filesystem or shell are blocked because this tool runs in a sandboxed browser/runtime model.

When should I turn on Quiet mode?

Use Quiet mode for sed -n style extraction. With quiet off, every line that survives the script is printed automatically. With quiet on, output appears only when the script uses commands such as p, P, =, or l.

What is the difference between basic and extended regex?

Basic mode matches traditional sed regular expressions where grouping and alternation are escaped, such as $foo\|bar$. Extended mode matches sed -E style patterns like (foo|bar) and ID-([0-9]+).

Can it edit files directly?

No. Paste text in and copy or download the result. Direct file reads/writes and shell execution are intentionally unavailable so the script cannot access anything outside the text you supplied.

Developer & Automation Access

Run it from the terminal

Same engine as this page, headless — via the gizza CLI:

gizza tool stream-editor "foo

keep this line
drop this line"

New to the CLI? Get gizza →

Open it by URL

Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:

https://gizza.ai/tools/stream-editor/?text=foo%0A%0Akeep%20this%20line%0Adrop%20this%20line&script=s%2Ffoo%2Fbar%2Fg%0A%2Fdrop%2Fd&quiet=true&ignore_case=true&whole_buffer=true&regex_flavor=basic&line_ending=lf&max_output_lines=100000

Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.