1 files changed, 54 insertions, 0 deletions
diff --git a/third_party/python/cram/cram/_process.py b/third_party/python/cram/cram/_process.py
new file mode 100644
index 0000000000..decdfbc3a7
--- /dev/null
+++ b/third_party/python/cram/cram/_process.py
@@ -0,0 +1,54 @@
+"""Utilities for running subprocesses"""
+
+import os
+import signal
+import subprocess
+import sys
+
+from cram._encoding import fsdecode
+
+__all__ = ['PIPE', 'STDOUT', 'execute']
+
+PIPE = subprocess.PIPE
+STDOUT = subprocess.STDOUT
+
+def _makeresetsigpipe():
+    """Make a function to reset SIGPIPE to SIG_DFL (for use in subprocesses).
+
+    Doing subprocess.Popen(..., preexec_fn=makeresetsigpipe()) will prevent
+    Python's SIGPIPE handler (SIG_IGN) from being inherited by the
+    child process.
+    """
+    if (sys.platform == 'win32' or
+        getattr(signal, 'SIGPIPE', None) is None): # pragma: nocover
+        return None
+    return lambda: signal.signal(signal.SIGPIPE, signal.SIG_DFL)
+
+def execute(args, stdin=None, stdout=None, stderr=None, cwd=None, env=None):
+    """Run a process and return its output and return code.
+
+    stdin may either be None or a string to send to the process.
+
+    stdout may either be None or PIPE. If set to PIPE, the process's output
+    is returned as a string.
+
+    stderr may either be None or STDOUT. If stdout is set to PIPE and stderr
+    is set to STDOUT, the process's stderr output will be interleaved with
+    stdout and returned as a string.
+
+    cwd sets the process's current working directory.
+
+    env can be set to a dictionary to override the process's environment
+    variables.
+
+    This function returns a 2-tuple of (output, returncode).
+    """
+    if sys.platform == 'win32': # pragma: nocover
+        args = [fsdecode(arg) for arg in args]
+
+    p = subprocess.Popen(args, stdin=PIPE, stdout=stdout, stderr=stderr,
+                         cwd=cwd, env=env, bufsize=-1,
+                         preexec_fn=_makeresetsigpipe(),
+                         close_fds=os.name == 'posix')
+    out, err = p.communicate(stdin)
+    return out, p.returncode