.. _auto_file_write:

*WRITE TO FILE*
===============

Modifies an existing file by replacing text content using exact string matching. Accepts a file attachment ID, file path, or attachment name, and supports replacing the first or all occurrences of the target string. Use this worker to perform in-place text edits on platform-managed files (max 500 MB).

When to use
-----------

Tagged: ``file``, ``file_write``, ``in_place``, ``replace``, ``string_replace``, ``text_edit``, ``write``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - File
     - file
     - file
     - —
     - ✓
     - The file to modify — supply a numeric attachment ID, an absolute/relative file path, or an attachment name registered on the platform; required.
   * - Old String
     - old_string
     - textarea
     - —
     - ✓
     - The exact literal text to search for in the file; must be non-empty and must differ from new_string — supports multi-line strings via the code editor.
   * - New String
     - new_string
     - textarea
     - —
     - ✓
     - The replacement text that will be written in place of old_string; may be an empty string to effectively delete the matched text — supports multi-line strings via the code editor.
   * - Replace All
     - replace_all
     - boolean
     - False
     - 
     - When true, every occurrence of old_string in the file is replaced; when false (default), only the first occurrence is replaced.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - File
     - file
     - file
     - The modified file returned as a platform file reference pointing to the same physical path that was overwritten in place.
   * - Replacements Made
     - replacements
     - number
     - Integer count of how many substitutions were actually performed; will be 0 if old_string was not found (which also raises an error).
   * - Bytes Written
     - bytes_written
     - number
     - Total number of bytes written back to disk after the replacement; useful for sanity-checking file size changes.
   * - Status
     - status
     - string
     - Human-readable success message summarising the number of replacements made and bytes written, e.g. 'Success: Made 2 replacement(s) in model.key (4096 bytes written)'.

Disciplines
-----------

- data.io.file

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>platform</code> schema. Worker id: <code>file_write</code>. Schema hash: <code>6efd4818b5ef</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>