add hg and python

1 files changed, 92 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Demo/scripts/update.py b/sys/src/cmd/python/Demo/scripts/update.py
new file mode 100755
index 000000000..c9360260e
--- /dev/null
+++ b/sys/src/cmd/python/Demo/scripts/update.py
@@ -0,0 +1,92 @@
+#! /usr/bin/env 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 re
+
+pat = '^([^: \t\n]+):([1-9][0-9]*):'
+prog = re.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:])
+
+if __name__ == "__main__":
+    main()