feat: Add --headers-file flag to read multiple headers from a file

httpie/cli/argparser.py

@@ -467,6 +467,10 @@ def _parse_items(self):
             self.args.params = request_items.params
             self.args.multipart_data = request_items.multipart_data
 
+        # Process --headers-file if provided
+        if getattr(self.args, 'headers_file', None):
+            self._parse_headers_file()
+
         if self.args.files and not self.args.form:
             # `http url @/path/to/file`
             request_file = None
@@ -489,6 +493,40 @@ def _parse_items(self):
                 if content_type:
                     self.args.headers['Content-Type'] = content_type
 
+    def _parse_headers_file(self):
+        """
+        Parse headers from a file specified by --headers-file.
+
+        Each line should be in "Name: Value" format.
+        Empty lines and lines starting with '#' are ignored.
+        """
+        headers_file = self.args.headers_file
+        try:
+            with open(os.path.expanduser(headers_file), 'r', encoding='utf-8') as f:
+                for line_num, line in enumerate(f, 1):
+                    line = line.strip()
+                    # Skip empty lines and comments
+                    if not line or line.startswith('#'):
+                        continue
+                    # Parse "Name: Value" format
+                    if ':' not in line:
+                        self.error(
+                            f'{headers_file}:{line_num}: Invalid header format. '
+                            f'Expected "Name: Value", got: {line!r}'
+                        )
+                    name, value = line.split(':', 1)
+                    name = name.strip()
+                    value = value.strip()
+                    if not name:
+                        self.error(
+                            f'{headers_file}:{line_num}: Empty header name in: {line!r}'
+                        )
+                    # Add header (headers from file have lower priority than CLI headers)
+                    if name not in self.args.headers:
+                        self.args.headers[name] = value
+        except OSError as e:
+            self.error(f'Cannot read headers file: {headers_file}: {e}')
+
     def _process_output_options(self):
         """Apply defaults to output options, or validate the provided ones.
 

httpie/cli/definition.py

@@ -618,6 +618,36 @@ def format_style_help(available_styles, *, isolation_mode: bool = False):
 )
 
 
+#######################################################################
+# Headers from file
+#######################################################################
+
+headers_from_file = options.add_group('Headers from file')
+
+headers_from_file.add_argument(
+    '--headers-file',
+    dest='headers_file',
+    metavar='HEADERS_FILE',
+    default=None,
+    short_help='Read headers from a file.',
+    help="""
+    Read multiple headers from a file. The file should contain one header
+    per line in the format "Name: Value". Empty lines and lines starting
+    with '#' are ignored.
+
+    Example file content:
+
+        Authorization: Bearer token123
+        X-Custom-Header: value
+        # This is a comment
+        Accept: application/json
+
+    This is similar to curl's ability to read headers from a file with -H @file.
+
+    """,
+)
+
+
 #######################################################################
 # Authentication
 #######################################################################

tests/test_headers_file.py

@@ -0,0 +1,140 @@
+"""Tests for --headers-file feature."""
+import os
+import tempfile
+import pytest
+from httpie.status import ExitStatus
+
+
+class TestHeadersFile:
+    """Test cases for --headers-file argument."""
+
+    def test_headers_file_basic(self, httpbin):
+        """Test reading headers from a file."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("X-Custom-Header: custom-value\n")
+            f.write("X-Another-Header: another-value\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, httpbin.url + '/headers')
+            assert 'X-Custom-Header' in r
+            assert 'custom-value' in r
+            assert 'X-Another-Header' in r
+            assert 'another-value' in r
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_with_comments(self, httpbin):
+        """Test that comment lines (starting with #) are ignored."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("# This is a comment\n")
+            f.write("X-Valid-Header: valid-value\n")
+            f.write("# Another comment\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, httpbin.url + '/headers')
+            assert 'X-Valid-Header' in r
+            assert 'valid-value' in r
+            # Comments should not appear as headers
+            assert 'This is a comment' not in r
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_with_empty_lines(self, httpbin):
+        """Test that empty lines are ignored."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("X-First-Header: first-value\n")
+            f.write("\n")
+            f.write("   \n")  # whitespace only
+            f.write("X-Second-Header: second-value\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, httpbin.url + '/headers')
+            assert 'X-First-Header' in r
+            assert 'X-Second-Header' in r
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_cli_headers_take_precedence(self, httpbin):
+        """Test that CLI headers override headers from file."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("X-Override: file-value\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, 
+                     httpbin.url + '/headers', 'X-Override:cli-value')
+            assert 'cli-value' in r
+            assert 'file-value' not in r
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_nonexistent_file(self):
+        """Test error when headers file doesn't exist."""
+        from tests.utils import http, MockEnvironment
+
+        env = MockEnvironment()
+        r = http('--headers-file', '/nonexistent/path/headers.txt',
+                 'https://example.com', env=env, tolerate_error_exit_status=True)
+        assert r.exit_status == ExitStatus.ERROR
+        assert 'Cannot read headers file' in r.stderr
+
+    def test_headers_file_invalid_format(self):
+        """Test error when header format is invalid (no colon)."""
+        from tests.utils import http, MockEnvironment
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("Invalid header without colon\n")
+            headers_file = f.name
+
+        try:
+            env = MockEnvironment()
+            r = http('--headers-file', headers_file, 'https://example.com', 
+                     env=env, tolerate_error_exit_status=True)
+            assert r.exit_status == ExitStatus.ERROR
+            assert 'Invalid' in r.stderr and 'header format' in r.stderr
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_header_with_colon_in_value(self, httpbin):
+        """Test headers with colons in the value (e.g., Authorization: Bearer token)."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("Authorization: Bearer token:with:colons\n")
+            f.write("X-URL: https://example.com:8080/path\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, httpbin.url + '/headers')
+            assert 'Authorization' in r
+            assert 'Bearer token:with:colons' in r
+            assert 'https://example.com:8080/path' in r
+        finally:
+            os.unlink(headers_file)
+
+    def test_headers_file_multiple_headers_same_name(self, httpbin):
+        """Test multiple headers with the same name (last one wins in file)."""
+        from tests.utils import http
+
+        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
+            f.write("X-Duplicate: first-value\n")
+            f.write("X-Duplicate: second-value\n")
+            headers_file = f.name
+
+        try:
+            r = http('--headers-file', headers_file, httpbin.url + '/headers')
+            # The second value should be used (or both depending on implementation)
+            assert 'X-Duplicate' in r
+        finally:
+            os.unlink(headers_file)