Created the UnixWatchCommandOutput file.

TODO: Add configurable time support.
      Possibly add the rest of watch's options as well

pwatch.py

@@ -0,0 +1,157 @@
+#!/usr/bin/python
+"""
+Based on the code that
+Lyle Scott, III wrote.
+lyle@digitalfoo.net
+
+Watches the output of a command in a
+scrollable curses window.
+"""
+import curses
+import sys
+import random
+import locale
+import threading
+import subprocess
+import time
+locale.setlocale(locale.LC_ALL,"")
+
+class UnixWatchCommand:
+    DOWN = 1
+    UP = -1
+    SPACE_KEY = 32
+    ESC_KEY = 27
+
+    PREFIX_SELECTED = '-'
+    PREFIX_DESELECTED = ''
+
+    outputLines = []
+    screen = None
+
+    def __init__(self, command):
+        self.stop = threading.Event()
+        self.timer=threading.Thread(target=self.display)
+        self.command = ' '.join(command)
+        self.screen = curses.initscr()
+        curses.noecho()
+        curses.cbreak()
+        self.screen.keypad(1)
+        self.screen.border(0)
+        self.topLineNum = 0
+        self.highlightLineNum = 0
+        self.markedLineNums = []
+        self.getOutputLines()
+        self.timer.start()
+        self.run()
+        self.timer.join()
+
+    def display(self):
+        while not self.stop.is_set():
+            try:
+                self.displayScreen()
+                time.sleep(1)
+            except:
+                break
+
+    def run(self):
+        while True:
+            try:
+                self.displayScreen()
+                # get user command
+                c = self.screen.getch()
+                if c == curses.KEY_UP:
+                    self.updown(self.UP)
+                elif c == curses.KEY_DOWN:
+                    self.updown(self.DOWN)
+                elif c == self.SPACE_KEY:
+                    self.markLine()
+                elif c == self.ESC_KEY:
+                    self.stop.set()
+                    break
+            except:
+                self.stop.set()
+                break
+
+
+    def markLine(self):
+        linenum = self.topLineNum + self.highlightLineNum
+        if linenum in self.markedLineNums:
+            self.markedLineNums.remove(linenum)
+        else:
+            self.markedLineNums.append(linenum)
+
+    def check_output(self, command):
+
+        process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE,
+                                   stderr=subprocess.STDOUT,
+                                   universal_newlines=True)
+        output,stderr = process.communicate()
+        retcode = process.poll()
+
+        if retcode:
+                raise subprocess.CalledProcessError(retcode, command,
+                                                    output=output[0])
+        return output.splitlines()
+
+    def getOutputLines(self):
+        self.outputLines = self.check_output(self.command)
+        self.nOutputLines = len(self.outputLines)
+
+    def displayScreen(self):
+        # clear screen
+        self.screen.clear()
+        self.getOutputLines()
+        # now paint the rows
+        top = self.topLineNum
+        bottom = self.topLineNum+curses.LINES
+        for (index,line,) in enumerate(self.outputLines[top:bottom]):
+            linenum = self.topLineNum + index
+            if linenum in self.markedLineNums:
+                prefix = self.PREFIX_SELECTED
+            else:
+                prefix = self.PREFIX_DESELECTED
+
+            #line = '%s %s' % (prefix, line,)
+            # highlight current line
+            if index != self.highlightLineNum:
+                self.screen.addstr(index, 0, line)
+            else:
+                self.screen.addstr(index, 0, line, curses.A_BOLD)
+        self.screen.refresh()
+
+    # move highlight up/down one line
+    def updown(self, increment):
+        nextLineNum = self.highlightLineNum + increment
+
+        # paging
+        if increment == self.UP and self.highlightLineNum == 0\
+           and self.topLineNum != 0:
+            self.topLineNum += self.UP
+            return
+        elif increment == self.DOWN and nextLineNum == curses.LINES\
+             and (self.topLineNum+curses.LINES) != self.nOutputLines:
+            self.topLineNum += self.DOWN
+            return
+
+        # scroll highlight line
+        if increment == self.UP and (self.topLineNum != 0 or\
+                                     self.highlightLineNum != 0):
+            self.highlightLineNum = nextLineNum
+        elif increment == self.DOWN and\
+             (self.topLineNum+self.highlightLineNum+1) != self.nOutputLines\
+             and self.highlightLineNum != curses.LINES:
+            self.highlightLineNum = nextLineNum
+
+    def restoreScreen(self):
+        curses.initscr()
+        curses.nocbreak()
+        curses.echo()
+        curses.endwin()
+
+    # catch any weird termination situations
+    def __del__(self):
+        self.restoreScreen()
+
+
+if __name__ == '__main__':
+    ih = UnixWatchCommand(sys.argv[1:])