Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 65b2eb9dfebe873e8ee5821f13d5a8c07d9c89c2 authored by Georg Brandl on 05 December 2010, 11:42:38 UTC
Fix title.
Fix title.
Tip revision: 65b2eb9
repeat.py
#! /usr/bin/env python3
"""repeat [-i SECONDS] <shell-command>
This simple program repeatedly (at 1-second intervals) executes the
shell command given on the command line and displays the output (or as
much of it as fits on the screen). It uses curses to paint each new
output on top of the old output, so that if nothing changes, the
screen doesn't change. This is handy to watch for changes in e.g. a
directory or process listing.
The -i option lets you override the sleep time between executions.
To end, hit Control-C.
"""
# Author: Guido van Rossum
# Disclaimer: there's a Linux program named 'watch' that does the same
# thing. Honestly, I didn't know of its existence when I wrote this!
# To do: add features until it has the same functionality as watch(1);
# then compare code size and development time.
import os
import sys
import time
import curses
import getopt
def main():
interval = 1.0
try:
opts, args = getopt.getopt(sys.argv[1:], "hi:")
except getopt.error as err:
print(err, file=sys.stderr)
sys.exit(2)
if not args:
print(__doc__)
sys.exit(0)
for opt, arg in opts:
if opt == "-i":
interval = float(arg)
if opt == "-h":
print(__doc__)
sys.exit(0)
cmd = " ".join(args)
cmd_really = cmd + " 2>&1"
p = os.popen(cmd_really, "r")
text = p.read()
sts = p.close()
text = addsts(interval, cmd, text, sts)
w = curses.initscr()
try:
while True:
w.erase()
try:
w.addstr(text)
except curses.error:
pass
w.refresh()
time.sleep(interval)
p = os.popen(cmd_really, "r")
text = p.read()
sts = p.close()
text = addsts(interval, cmd, text, sts)
finally:
curses.endwin()
def addsts(interval, cmd, text, sts):
now = time.strftime("%H:%M:%S")
text = "%s, every %g sec: %s\n%s" % (now, interval, cmd, text)
if sts:
msg = "Exit status: %d; signal: %d" % (sts>>8, sts&0xFF)
if text and not text.endswith("\n"):
msg = "\n" + msg
text += msg
return text
main()