-o/--output option, closes #9

README.md

@@ -46,6 +46,18 @@ This will output the contents of every file, with each file preceded by its rela
   files-to-prompt path/to/directory --ignore "*.log" --ignore "temp*"
   ```
 
+- `c/--cxml`: Output in Claude XML format.
+
+  ```bash
+  files-to-prompt path/to/directory --cxml
+  ```
+
+- `-o/--output <file>`: Write the output to a file instead of printing it to the console.
+
+  ```bash
+  files-to-prompt path/to/directory -o output.txt
+  ```
+
 ### Example
 
 Suppose you have a directory structure like this:

files_to_prompt/cli.py

@@ -25,29 +25,29 @@ def read_gitignore(path):
     return []
 
 
-def print_path(path, content, xml):
+def print_path(writer, path, content, xml):
     if xml:
-        print_as_xml(path, content)
+        print_as_xml(writer, path, content)
     else:
-        print_default(path, content)
+        print_default(writer, path, content)
 
 
-def print_default(path, content):
-    click.echo(path)
-    click.echo("---")
-    click.echo(content)
-    click.echo()
-    click.echo("---")
+def print_default(writer, path, content):
+    writer(path)
+    writer("---")
+    writer(content)
+    writer("")
+    writer("---")
 
 
-def print_as_xml(path, content):
+def print_as_xml(writer, path, content):
     global global_index
-    click.echo(f'<document index="{global_index}">')
-    click.echo(f"<source>{path}</source>")
-    click.echo("<document_content>")
-    click.echo(content)
-    click.echo("</document_content>")
-    click.echo("</document>")
+    writer(f'<document index="{global_index}">')
+    writer(f"<source>{path}</source>")
+    writer("<document_content>")
+    writer(content)
+    writer("</document_content>")
+    writer("</document>")
     global_index += 1
 
 
@@ -57,12 +57,13 @@ def process_path(
     ignore_gitignore,
     gitignore_rules,
     ignore_patterns,
+    writer,
     claude_xml,
 ):
     if os.path.isfile(path):
         try:
             with open(path, "r") as f:
-                print_path(path, f.read(), claude_xml)
+                print_path(writer, path, f.read(), claude_xml)
         except UnicodeDecodeError:
             warning_message = f"Warning: Skipping file {path} due to UnicodeDecodeError"
             click.echo(click.style(warning_message, fg="red"), err=True)
@@ -96,7 +97,7 @@ def process_path(
                 file_path = os.path.join(root, file)
                 try:
                     with open(file_path, "r") as f:
-                        print_path(file_path, f.read(), claude_xml)
+                        print_path(writer, file_path, f.read(), claude_xml)
                 except UnicodeDecodeError:
                     warning_message = (
                         f"Warning: Skipping file {file_path} due to UnicodeDecodeError"
@@ -123,6 +124,13 @@ def process_path(
     default=[],
     help="List of patterns to ignore",
 )
+@click.option(
+    "output_file",
+    "-o",
+    "--output",
+    type=click.Path(writable=True),
+    help="Output to a file instead of stdout",
+)
 @click.option(
     "claude_xml",
     "-c",
@@ -131,7 +139,9 @@ def process_path(
     help="Output in XML-ish format suitable for Claude's long context window.",
 )
 @click.version_option()
-def cli(paths, include_hidden, ignore_gitignore, ignore_patterns, claude_xml):
+def cli(
+    paths, include_hidden, ignore_gitignore, ignore_patterns, output_file, claude_xml
+):
     """
     Takes one or more paths to files or directories and outputs every file,
     recursively, each one preceded with its filename like this:
@@ -162,20 +172,28 @@ def cli(paths, include_hidden, ignore_gitignore, ignore_patterns, claude_xml):
     global global_index
     global_index = 1
     gitignore_rules = []
+    writer = click.echo
+    fp = None
+    if output_file:
+        fp = open(output_file, "w")
+        writer = lambda s: print(s, file=fp)
     for path in paths:
         if not os.path.exists(path):
             raise click.BadArgumentUsage(f"Path does not exist: {path}")
         if not ignore_gitignore:
             gitignore_rules.extend(read_gitignore(os.path.dirname(path)))
         if claude_xml and path == paths[0]:
-            click.echo("<documents>")
+            writer("<documents>")
         process_path(
             path,
             include_hidden,
             ignore_gitignore,
             gitignore_rules,
             ignore_patterns,
+            writer,
             claude_xml,
         )
     if claude_xml:
-        click.echo("</documents>")
+        writer("</documents>")
+    if fp:
+        fp.close()

tests/test_files_to_prompt.py

@@ -222,3 +222,35 @@ Contents of file2.txt
 </documents>
 """
         assert expected.strip() == actual.strip()
+
+
+@pytest.mark.parametrize("arg", ("-o", "--output"))
+def test_output_option(tmpdir, arg):
+    runner = CliRunner()
+    with tmpdir.as_cwd():
+        os.makedirs("test_dir")
+        with open("test_dir/file1.txt", "w") as f:
+            f.write("Contents of file1.txt")
+        with open("test_dir/file2.txt", "w") as f:
+            f.write("Contents of file2.txt")
+        output_file = "output.txt"
+        result = runner.invoke(
+            cli, ["test_dir", arg, output_file], catch_exceptions=False
+        )
+        assert result.exit_code == 0
+        assert not result.output
+        with open(output_file, "r") as f:
+            actual = f.read()
+        expected = """
+test_dir/file1.txt
+---
+Contents of file1.txt
+
+---
+test_dir/file2.txt
+---
+Contents of file2.txt
+
+---
+"""
+        assert expected.strip() == actual.strip()