run_command_grep
Run any command and return only lines matching a case-insensitive regex pattern. Filters long output in-process, replacing Unix grep, to find errors or specific tests.
Instructions
Runs a command and returns only lines matching the given pattern (case-insensitive regex). Use instead of run_safe_command when you know in advance that the output will be long and you only care about a specific pattern (e.g. searching for 'error' in build output, finding a specific test in test runner output). The command runs in the directory given by the cwd parameter and is subject to the same safety checks as run_safe_command. This is the replacement for Unix 'grep' on Windows — filtering happens in-process, so grep/head/tail are not needed. LIMITATION: The matches themselves can be too long — if you need more control, use run_safe_command first and then read_log_slice on the saved log file. Instead of Unix patterns like 'cmd /c ... | findstr ... & echo DONE' use THIS tool with a pattern — it filters in-process. If the task targets a project other than the primary one (MCP_PROJECT_ROOT), always pass the "cwd" parameter. Get the list of allowed roots via the "list_allowed_roots" tool.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cwd | No | The directory in which the command will be run (must be inside MCP_PROJECT_ROOT / MCP_EXTRA_ROOTS). Default: the primary project (MCP_PROJECT_ROOT). | |
| command | Yes | Command to execute | |
| pattern | Yes | Pattern (regular expression) to filter lines | |
| timeoutMs | No | Timeout in milliseconds (1,000 – 600,000, default 60,000). You can extend it for longer tests/builds, e.g. 180,000 for jest. |