commit -- why not...
diff --git a/Demo/comparisons/systemtest.py b/Demo/comparisons/systemtest.py
new file mode 100755
index 0000000..26d9f54
--- /dev/null
+++ b/Demo/comparisons/systemtest.py
@@ -0,0 +1,74 @@
+#! /usr/local/bin/python
+
+# 3) System Test
+#
+# Given a list of directories, report any bogus symbolic links contained
+# anywhere in those subtrees. A bogus symbolic link is one that cannot
+# be resolved because it points to a nonexistent or otherwise
+# unresolvable file. Do *not* use an external find executable.
+# Directories may be very very deep. Print a warning immediately if the
+# system you're running on doesn't support symbolic links.
+
+# This implementation:
+# - takes one optional argument, using the current directory as default
+# - uses chdir to increase performance
+# - sorts the names per directory
+# - prints output lines of the form "path1 -> path2" as it goes
+# - prints error messages about directories it can't list or chdir into
+
+import os
+import sys
+from stat import *
+
+def main():
+ try:
+ # Note: can't test for presence of lstat -- it's always there
+ dummy = os.readlink
+ except AttributeError:
+ print "This system doesn't have symbolic links"
+ sys.exit(0)
+ if sys.argv[1:]:
+ prefix = sys.argv[1]
+ else:
+ prefix = ''
+ if prefix:
+ os.chdir(prefix)
+ if prefix[-1:] != '/': prefix = prefix + '/'
+ reportboguslinks(prefix)
+ else:
+ reportboguslinks('')
+
+def reportboguslinks(prefix):
+ try:
+ names = os.listdir('.')
+ except os.error, msg:
+ print "%s%s: can't list: %s" % (prefix, '.', msg)
+ return
+ names.sort()
+ for name in names:
+ if name == os.curdir or name == os.pardir:
+ continue
+ try:
+ mode = os.lstat(name)[ST_MODE]
+ except os.error:
+ print "%s%s: can't stat: %s" % (prefix, name, msg)
+ continue
+ if S_ISLNK(mode):
+ try:
+ os.stat(name)
+ except os.error:
+ print "%s%s -> %s" % \
+ (prefix, name, os.readlink(name))
+ elif S_ISDIR(mode):
+ try:
+ os.chdir(name)
+ except os.error, msg:
+ print "%s%s: can't chdir: %s" % \
+ (prefix, name, msg)
+ continue
+ try:
+ reportboguslinks(prefix + name + '/')
+ finally:
+ os.chdir('..')
+
+main()