Fixed the output wrapping for Alembic message output, so that

we either get the terminal width for "pretty printing" with
indentation, or if not we just output the text as is; in any
case the text won't be wrapped too short. #135

diff --git a/alembic/util.py b/alembic/util.py
index a8750a2c145d967c6ec313538e8daa130c340c8c..b9565480be3eeb087621607f3ec6b41411ae1a97 100644 (file)
--- a/alembic/util.py
+++ b/alembic/util.py
@@ -30,10 +30,17 @@ if not sqla_07:
 from sqlalchemy.util import format_argspec_plus, update_wrapper
 from sqlalchemy.util.compat import inspect_getfullargspec
 
+
 try:
-    width = int(os.environ['COLUMNS'])
-except (KeyError, ValueError):
-    width = 80
+    import fcntl
+    import termios
+    import struct
+    ioctl = fcntl.ioctl(0, termios.TIOCGWINSZ,
+                           struct.pack('HHHH', 0, 0, 0, 0))
+    _h, TERMWIDTH, _hp, _wp = struct.unpack('HHHH', ioctl)
+except (ImportError, IOError):
+    TERMWIDTH = None
+
 
 def template_to_file(template_file, dest, **kw):
     with open(dest, 'w') as f:
@@ -171,11 +178,17 @@ def warn(msg):
     warnings.warn(msg)
 
 def msg(msg, newline=True):
-    lines = textwrap.wrap(msg, width)
-    if len(lines) > 1:
-        for line in lines[0:-1]:
-            write_outstream(sys.stdout, "  ", line, "\n")
-    write_outstream(sys.stdout, "  ", lines[-1], ("\n" if newline else ""))
+    if TERMWIDTH is None:
+        write_outstream(sys.stdout, msg)
+        if newline:
+            write_outstream(sys.stdout, "\n")
+    else:
+        # left indent output lines
+        lines = textwrap.wrap(msg, TERMWIDTH)
+        if len(lines) > 1:
+            for line in lines[0:-1]:
+                write_outstream(sys.stdout, "  ", line, "\n")
+        write_outstream(sys.stdout, "  ", lines[-1], ("\n" if newline else ""))
 
 def load_python_file(dir_, filename):
     """Load a file from the given path as a Python module."""

diff --git a/docs/build/changelog.rst b/docs/build/changelog.rst
index 364bc8408628e44a8a2e7f6dbc4f58480552bbf4..96ed78303eb83570bb9c3129bc619fd309f8109d 100644 (file)
--- a/docs/build/changelog.rst
+++ b/docs/build/changelog.rst
@@ -7,6 +7,15 @@ Changelog
     :version: 0.6.1
     :released: no release date
 
+    .. change::
+      :tags: bug
+      :tickets: 135
+
+      Fixed the output wrapping for Alembic message output, so that
+      we either get the terminal width for "pretty printing" with
+      indentation, or if not we just output the text as is; in any
+      case the text won't be wrapped too short.
+
     .. change::
       :tags: bug
       :tickets: 145