Initial revision

diff --git a/Demo/scripts/update.py b/Demo/scripts/update.py
new file mode 100755 (executable)
index 0000000..e8f6283
--- /dev/null
+++ b/Demo/scripts/update.py
@@ -0,0 +1,91 @@
+#! /usr/local/bin/python
+
+# Update a bunch of files according to a script.
+# The input file contains lines of the form <filename>:<lineno>:<text>,
+# meaning that the given line of the given file is to be replaced
+# by the given text.  This is useful for performing global substitutions
+# on grep output: 
+
+import os
+import sys
+import regex
+
+pat = '^\([^: \t\n]+\):\([1-9][0-9]*\):'
+prog = regex.compile(pat)
+
+class FileObj:
+       def __init__(self, filename):
+               self.filename = filename
+               self.changed = 0
+               try:
+                       self.lines = open(filename, 'r').readlines()
+               except IOError, msg:
+                       print '*** Can\'t open "%s":' % filename, msg
+                       self.lines = None
+                       return
+               print 'diffing', self.filename
+
+       def finish(self):
+               if not self.changed:
+                       print 'no changes to', self.filename
+                       return
+               try:
+                       os.rename(self.filename, self.filename + '~')
+                       fp = open(self.filename, 'w')
+               except (os.error, IOError), msg:
+                       print '*** Can\'t rewrite "%s":' % self.filename, msg
+                       return
+               print 'writing', self.filename
+               for line in self.lines:
+                       fp.write(line)
+               fp.close()
+               self.changed = 0
+
+       def process(self, lineno, rest):
+               if self.lines is None:
+                       print '(not processed): %s:%s:%s' % (
+                                 self.filename, lineno, rest),
+                       return
+               i = eval(lineno) - 1
+               if not 0 <= i < len(self.lines):
+                       print '*** Line number out of range: %s:%s:%s' % (
+                                 self.filename, lineno, rest),
+                       return
+               if self.lines[i] == rest:
+                       print '(no change): %s:%s:%s' % (
+                                 self.filename, lineno, rest),
+                       return
+               if not self.changed:
+                       self.changed = 1
+               print '%sc%s' % (lineno, lineno)
+               print '<', self.lines[i],
+               print '---'
+               self.lines[i] = rest
+               print '>', self.lines[i],
+
+def main():
+       if sys.argv[1:]:
+               try:
+                       fp = open(sys.argv[1], 'r')
+               except IOError, msg:
+                       print 'Can\'t open "%s":' % sys.argv[1], msg
+                       sys.exit(1)
+       else:
+               fp = sys.stdin
+       curfile = None
+       while 1:
+               line = fp.readline()
+               if not line:
+                       if curfile: curfile.finish()
+                       break
+               n = prog.match(line)
+               if n < 0:
+                       print 'Funny line:', line,
+                       continue
+               filename, lineno = prog.group(1, 2)
+               if not curfile or filename <> curfile.filename:
+                       if curfile: curfile.finish()
+                       curfile = FileObj(filename)
+               curfile.process(lineno, line[n:])
+
+main()