1 files changed, 133 insertions, 0 deletions
diff --git a/pre_commit/languages/pygrep.py b/pre_commit/languages/pygrep.py
new file mode 100644
index 0000000..72a9345
--- /dev/null
+++ b/pre_commit/languages/pygrep.py
@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+import argparse
+import re
+import sys
+from collections.abc import Sequence
+from re import Pattern
+from typing import NamedTuple
+
+from pre_commit import lang_base
+from pre_commit import output
+from pre_commit.prefix import Prefix
+from pre_commit.xargs import xargs
+
+ENVIRONMENT_DIR = None
+get_default_version = lang_base.basic_get_default_version
+health_check = lang_base.basic_health_check
+install_environment = lang_base.no_install
+in_env = lang_base.no_env
+
+
+def _process_filename_by_line(pattern: Pattern[bytes], filename: str) -> int:
+    retv = 0
+    with open(filename, 'rb') as f:
+        for line_no, line in enumerate(f, start=1):
+            if pattern.search(line):
+                retv = 1
+                output.write(f'{filename}:{line_no}:')
+                output.write_line_b(line.rstrip(b'\r\n'))
+    return retv
+
+
+def _process_filename_at_once(pattern: Pattern[bytes], filename: str) -> int:
+    retv = 0
+    with open(filename, 'rb') as f:
+        contents = f.read()
+        match = pattern.search(contents)
+        if match:
+            retv = 1
+            line_no = contents[:match.start()].count(b'\n')
+            output.write(f'{filename}:{line_no + 1}:')
+
+            matched_lines = match[0].split(b'\n')
+            matched_lines[0] = contents.split(b'\n')[line_no]
+
+            output.write_line_b(b'\n'.join(matched_lines))
+    return retv
+
+
+def _process_filename_by_line_negated(
+        pattern: Pattern[bytes],
+        filename: str,
+) -> int:
+    with open(filename, 'rb') as f:
+        for line in f:
+            if pattern.search(line):
+                return 0
+        else:
+            output.write_line(filename)
+            return 1
+
+
+def _process_filename_at_once_negated(
+        pattern: Pattern[bytes],
+        filename: str,
+) -> int:
+    with open(filename, 'rb') as f:
+        contents = f.read()
+    match = pattern.search(contents)
+    if match:
+        return 0
+    else:
+        output.write_line(filename)
+        return 1
+
+
+class Choice(NamedTuple):
+    multiline: bool
+    negate: bool
+
+
+FNS = {
+    Choice(multiline=True, negate=True): _process_filename_at_once_negated,
+    Choice(multiline=True, negate=False): _process_filename_at_once,
+    Choice(multiline=False, negate=True): _process_filename_by_line_negated,
+    Choice(multiline=False, negate=False): _process_filename_by_line,
+}
+
+
+def run_hook(
+        prefix: Prefix,
+        entry: str,
+        args: Sequence[str],
+        file_args: Sequence[str],
+        *,
+        is_local: bool,
+        require_serial: bool,
+        color: bool,
+) -> tuple[int, bytes]:
+    cmd = (sys.executable, '-m', __name__, *args, entry)
+    return xargs(cmd, file_args, color=color)
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(
+        description=(
+            'grep-like finder using python regexes.  Unlike grep, this tool '
+            'returns nonzero when it finds a match and zero otherwise.  The '
+            'idea here being that matches are "problems".'
+        ),
+    )
+    parser.add_argument('-i', '--ignore-case', action='store_true')
+    parser.add_argument('--multiline', action='store_true')
+    parser.add_argument('--negate', action='store_true')
+    parser.add_argument('pattern', help='python regex pattern.')
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    flags = re.IGNORECASE if args.ignore_case else 0
+    if args.multiline:
+        flags |= re.MULTILINE | re.DOTALL
+
+    pattern = re.compile(args.pattern.encode(), flags)
+
+    retv = 0
+    process_fn = FNS[Choice(multiline=args.multiline, negate=args.negate)]
+    for filename in args.filenames:
+        retv |= process_fn(pattern, filename)
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())