Merge pull request #282 from cs50/pexpect

removed pexpect, fixed windows

.gitignore

@@ -1,4 +1,5 @@
 .*
 !.gitignore
 !.travis.yml
+help50.egg*
 __pycache__/

help50/__main__.py

@@ -4,7 +4,6 @@
 import re
 import shlex
 import sys
-import tempfile
 import traceback
 
 from argparse import ArgumentParser, REMAINDER
@@ -14,6 +13,12 @@
 
 from . import __version__, internal, Error
 
+ON_WINDOWS = os.name == "nt"
+
+if ON_WINDOWS:
+    # Fix termcolor colors on Windows
+    import colorama
+    colorama.init()
 
 def excepthook(cls, exc, tb):
     if (issubclass(cls, lib50.Error) or issubclass(cls, Error)) and exc.args:
@@ -60,7 +65,6 @@ def main():
                                         "students understand error messages.")
     parser.add_argument("-s", "--slug", help="identifier indicating from where to download helpers", default="cs50/helpers/master")
     parser.add_argument("-d", "--dev", help="slug will be treated as a local path, useful for developing helpers (implies --verbose)", action="store_true")
-    parser.add_argument("-i", "--interactive", help="read command output from stdin instead of running a command", action="store_true")
     parser.add_argument("-v", "--verbose", help="display the full tracebacks of any errors", action="store_true")
     parser.add_argument("-V", "--version", action="version", version=f"%(prog)s {__version__}")
     parser.add_argument("command", nargs=REMAINDER,
@@ -72,25 +76,42 @@ def main():
 
     excepthook.verbose = args.verbose
 
+    if args.command:
+        command = " ".join(shlex.quote(word) for word in args.command)
+        script = b""
+
+        # pty isn't supported on Windows
+        if ON_WINDOWS:
+            import subprocess
+            proc = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+            for b in iter(lambda: proc.stdout.read(1), b""):
+                script += b
+                sys.stdout.buffer.write(b)
+                sys.stdout.flush()
+        else:
+            import pty
+            def master_read(fd):
+                nonlocal script
+                data = os.read(fd, 1024)
+                script += data
+                return data
+
+            old_env = os.environ.copy()
 
-    if args.interactive:
-        script = sys.stdin.read()
-    elif args.command:
-        # Capture stdout and stderr from process, and print it out
-        with tempfile.TemporaryFile(mode="r+b") as temp:
-            env = os.environ.copy()
             # Hack to prevent some programs from wrapping their error messages
-            env["COLUMNS"] = "5050"
-            proc = pexpect.spawn(f"bash -lc \"{' '.join(shlex.quote(word) for word in args.command)}\"", env=env)
-            proc.logfile_read = temp
-            proc.interact()
-            proc.close()
-
-            temp.seek(0)
-            script = temp.read().decode().replace("\r\n", "\n")
+            os.environ.update({"COLUMNS": "5050"})
+            try:
+                # Run the process in a pseudo-terminal e.g., to preserve colored output
+                pty.spawn(["bash", "-lc", command], master_read)
+            finally:
+                os.environ.clear()
+                os.environ.update(old_env)
+
+        script = script.decode().replace("\r\n", "\n")
     else:
         raise Error("Careful, you forgot to tell me with which command you "
                     "need help!")
+
     termcolor.cprint("\nAsking for help...\n", "yellow")
 
     try:

setup.py

@@ -12,7 +12,7 @@
     ],
     license="GPLv3",
     description="This is help50, a command-line tool that helps students understand error messages.",
-    install_requires=["pexpect", "termcolor", "lib50>=1.1.10"],
+    install_requires=["colorama", "termcolor", "lib50>=1.1.10"],
     keywords="help50",
     name="help50",
     packages=["help50"],
@@ -21,5 +21,5 @@
     },
     py_requires="3.6",
     url="https://github.com/cs50/help50",
-    version="3.0.0"
+    version="3.0.1"
 )