CLI Regex Tester & Command Builder

Regular expressions are the bedrock of command-line text processing. However, matching POSIX basic vs extended regex rules can lead to unexpected behaviors when transitioning between tools.

Use this interactive playground to test regex patterns, view matched lines in real-time, and compile matching commands for grep and sed.

Interactive Regex Tester

Specify a regex pattern and match options to test matches against the log database, and view the compiled CLI command.

[ INPUT LOGS & MATCH HIGHLIGHTS ]

Paste logs or test data: Simulated Console Output:

[ REGEX CONFIGURATION ]

Regex Pattern

Target Utility Command

Options:

Case-insensitive (-i) Use Extended Regex (-E)

[ COMPILED CLI COMMAND ]

--- ### POSIX Basic vs Extended Regex * **Basic Regular Expressions (BRE):** Default behavior in `grep` and `sed`. Metacharacters like `|`, `+`, `?`, `{`, and `(` are treated as literal text characters unless escaped with a backslash (e.g. `\(match\)`). * **Extended Regular Expressions (ERE):** Triggered using `-E`. Characters like `|` (alternation) and `+` (one-or-more) are recognized as operators directly without backslash escaping.