Initial revision
diff --git a/Demo/scripts/eqfix.py b/Demo/scripts/eqfix.py
new file mode 100755
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--- /dev/null
+++ b/Demo/scripts/eqfix.py
@@ -0,0 +1,168 @@
+#! /ufs/guido/bin/sgi/python
+#! /usr/local/python
+
+# Fix Python source files to use the new equality test operator,
+# i.e.,
+# if x == y: ...
+# instead of
+# if x = y: ...
+#
+# Command line arguments are files or directories to be processed.
+# Directories are searched recursively for files whose name looks
+# like a python module.
+# Symbolic links are always ignored (except as explicit directory
+# arguments). Of course, the original file is kept as a back-up
+# (with a "~" attached to its name).
+#
+# Changes made are reported to stdout in a diff-like format.
+#
+# Undoubtedly you can do this using find and sed or perl, but this is
+# a nice example of Python code that recurses down a directory tree
+# and uses regular expressions. Also note several subtleties like
+# preserving the file's mode and avoiding to even write a temp file
+# when no changes are needed for a file.
+#
+# NB: by changing only the function fixline() you can turn this
+# into a program for a different change to Python programs...
+
+import sys
+import regex
+import posix
+import path
+from stat import *
+
+err = sys.stderr.write
+dbg = err
+rep = sys.stdout.write
+
+def main():
+ bad = 0
+ if not sys.argv[1:]: # No arguments
+ err('usage: ' + argv[0] + ' file-or-directory ...\n')
+ sys.exit(2)
+ for arg in sys.argv[1:]:
+ if path.isdir(arg):
+ if recursedown(arg): bad = 1
+ elif path.islink(arg):
+ err(arg + ': will not process symbolic links\n')
+ bad = 1
+ else:
+ if fix(arg): bad = 1
+ sys.exit(bad)
+
+ispythonprog = regex.compile('^[a-zA-Z0-9_]+\.py$')
+def ispython(name):
+ return ispythonprog.match(name) >= 0
+
+def recursedown(dirname):
+ dbg('recursedown(' + `dirname` + ')\n')
+ bad = 0
+ try:
+ names = posix.listdir(dirname)
+ except posix.error, msg:
+ err(dirname + ': cannot list directory: ' + `msg` + '\n')
+ return 1
+ names.sort()
+ subdirs = []
+ for name in names:
+ if name in ('.', '..'): continue
+ fullname = path.join(dirname, name)
+ if path.islink(fullname): pass
+ elif path.isdir(fullname):
+ subdirs.append(fullname)
+ elif ispython(name):
+ if fix(fullname): bad = 1
+ for fullname in subdirs:
+ if recursedown(fullname): bad = 1
+ return bad
+
+def fix(filename):
+ dbg('fix(' + `filename` + ')\n')
+ try:
+ f = open(filename, 'r')
+ except IOError, msg:
+ err(filename + ': cannot open: ' + `msg` + '\n')
+ return 1
+ head, tail = path.split(filename)
+ tempname = path.join(head, '@' + tail)
+ g = None
+ # If we find a match, we rewind the file and start over but
+ # now copy everything to a temp file.
+ lineno = 0
+ while 1:
+ line = f.readline()
+ if not line: break
+ lineno = lineno + 1
+ while line[-2:] == '\\\n':
+ nextline = f.readline()
+ if not nextline: break
+ line = line + nextline
+ lineno = lineno + 1
+ newline = fixline(line)
+ if newline != line:
+ if g is None:
+ try:
+ g = open(tempname, 'w')
+ except IOError, msg:
+ f.close()
+ err(tempname+': cannot create: '+\
+ `msg`+'\n')
+ return 1
+ f.seek(0)
+ lineno = 0
+ rep(filename + ':\n')
+ continue # restart from the beginning
+ rep(`lineno` + '\n')
+ rep('< ' + line)
+ rep('> ' + newline)
+ if g is not None:
+ g.write(newline)
+
+ # End of file
+ f.close()
+ if not g: return 0 # No changes
+
+ # Finishing touch -- move files
+
+ # First copy the file's mode to the temp file
+ try:
+ statbuf = posix.stat(filename)
+ posix.chmod(tempname, statbuf[ST_MODE] & 07777)
+ except posix.error, msg:
+ err(tempname + ': warning: chmod failed (' + `msg` + ')\n')
+ # Then make a backup of the original file as filename~
+ try:
+ posix.rename(filename, filename + '~')
+ except posix.error, msg:
+ err(filename + ': warning: backup failed (' + `msg` + ')\n')
+ # Now move the temp file to the original file
+ try:
+ posix.rename(tempname, filename)
+ except posix.error, msg:
+ err(filename + ': rename failed (' + `msg` + ')\n')
+ return 1
+ # Return succes
+ return 0
+
+PAT1 = '\<\(if\|elif\|while\)\>[\0-\377]*[^<>!=]\(=\)[^=][\0-\377]*[^[]:[^]]'
+# \2 \3
+PAT2 = '\<return\>[\0-\377]*[^<>!=]\(=\)[^=]'
+# \4
+PAT = '^[ \t]*\(' + PAT1 + '\|' + PAT2 + '\)'
+# \1
+prog = regex.compile(PAT)
+
+def fixline(line):
+ while prog.match(line) >= 0:
+ regs = prog.regs
+ if regs[3] == (-1, -1):
+ a, b = regs[4]
+ else:
+ a, b = regs[3]
+ if not 0 < a < b < len(line):
+ dbg('Weird: ' + line)
+ break
+ line = line[:a] + '==' + line[b:]
+ return line
+
+main()