Implement a simplified xargs in python

pre_commit/languages/helpers.py

@@ -12,18 +12,3 @@ def environment_dir(ENVIRONMENT_DIR, language_version):
         return None
     else:
         return '{0}-{1}'.format(ENVIRONMENT_DIR, language_version)
-
-
-def file_args_to_stdin(file_args):
-    return '\0'.join(list(file_args) + [''])
-
-
-def run_hook(cmd_args, file_args):
-    return cmd_output(
-        # Use -s 4000 (slightly less than posix mandated minimum)
-        # This is to prevent "xargs: ... Bad file number" on windows
-        'xargs', '-0', '-s4000', *cmd_args,
-        stdin=file_args_to_stdin(file_args),
-        retcode=None,
-        encoding=None
-    )

pre_commit/languages/node.py

@@ -8,6 +8,7 @@ from pre_commit.envcontext import envcontext
 from pre_commit.envcontext import Var
 from pre_commit.languages import helpers
 from pre_commit.util import clean_path_on_failure
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = 'node_env'
@@ -63,6 +64,4 @@ def install_environment(
 
 def run_hook(repo_cmd_runner, hook, file_args):
     with in_env(repo_cmd_runner, hook['language_version']):
-        return helpers.run_hook(
-            (hook['entry'],) + tuple(hook['args']), file_args,
-        )
+        return xargs((hook['entry'],) + tuple(hook['args']), file_args)

pre_commit/languages/pcre.py

@@ -2,8 +2,8 @@ from __future__ import unicode_literals
 
 from sys import platform
 
-from pre_commit.languages import helpers
 from pre_commit.util import shell_escape
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = None
@@ -24,7 +24,7 @@ def run_hook(repo_cmd_runner, hook, file_args):
     )
 
     # For PCRE the entry is the regular expression to match
-    return helpers.run_hook(
+    return xargs(
         (
             'sh', '-c',
             # Grep usually returns 0 for matches, and nonzero for non-matches

pre_commit/languages/python.py

@@ -10,6 +10,7 @@ from pre_commit.envcontext import UNSET
 from pre_commit.envcontext import Var
 from pre_commit.languages import helpers
 from pre_commit.util import clean_path_on_failure
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = 'py_env'
@@ -80,6 +81,4 @@ def install_environment(
 
 def run_hook(repo_cmd_runner, hook, file_args):
     with in_env(repo_cmd_runner, hook['language_version']):
-        return helpers.run_hook(
-            (hook['entry'],) + tuple(hook['args']), file_args,
-        )
+        return xargs((hook['entry'],) + tuple(hook['args']), file_args)

pre_commit/languages/ruby.py

@@ -12,6 +12,7 @@ from pre_commit.util import CalledProcessError
 from pre_commit.util import clean_path_on_failure
 from pre_commit.util import resource_filename
 from pre_commit.util import tarfile_open
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = 'rbenv'
@@ -125,6 +126,4 @@ def install_environment(
 
 def run_hook(repo_cmd_runner, hook, file_args):
     with in_env(repo_cmd_runner, hook['language_version']):
-        return helpers.run_hook(
-            (hook['entry'],) + tuple(hook['args']), file_args,
-        )
+        return xargs((hook['entry'],) + tuple(hook['args']), file_args)

pre_commit/languages/script.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from pre_commit.languages import helpers
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = None
@@ -16,7 +16,7 @@ def install_environment(
 
 
 def run_hook(repo_cmd_runner, hook, file_args):
-    return helpers.run_hook(
+    return xargs(
         (repo_cmd_runner.prefix_dir + hook['entry'],) + tuple(hook['args']),
         file_args,
     )

pre_commit/languages/system.py

@@ -2,7 +2,7 @@ from __future__ import unicode_literals
 
 import shlex
 
-from pre_commit.languages import helpers
+from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = None
@@ -18,6 +18,6 @@ def install_environment(
 
 
 def run_hook(repo_cmd_runner, hook, file_args):
-    return helpers.run_hook(
+    return xargs(
         tuple(shlex.split(hook['entry'])) + tuple(hook['args']), file_args,
     )