Python: Uptime script
Saturday, November 19th, 2005I've been writing Python for a grand total of 2 days. I recently wrote a little Python script to print a Linx or UNIX system's uptime. This took about 10 minutes to write, so I was pretty pleased. It even runs well on a 75MHz Busybox embedded Linux system. Check it out:
PYTHON:
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#!/usr/bin/python
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import os
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#----------------------------------------
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# Gives a human-readable uptime string
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def uptime():
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try:
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f = open( "/proc/uptime" )
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contents = f.read().split()
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f.close()
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except:
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return "Cannot open uptime file: /proc/uptime"
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total_seconds = float(contents[0])
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# Helper vars:
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MINUTE = 60
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HOUR = MINUTE * 60
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DAY = HOUR * 24
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# Get the days, hours, etc:
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days = int( total_seconds / DAY )
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hours = int( ( total_seconds % DAY ) / HOUR )
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minutes = int( ( total_seconds % HOUR ) / MINUTE )
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seconds = int( total_seconds % MINUTE )
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# Build up the pretty string (like this: "N days, N hours, N minutes, N seconds")
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string = ""
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if days> 0:
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string += str(days) + " " + (days == 1 and "day" or "days" ) + ", "
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if len(string)> 0 or hours> 0:
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string += str(hours) + " " + (hours == 1 and "hour" or "hours" ) + ", "
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if len(string)> 0 or minutes> 0:
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string += str(minutes) + " " + (minutes == 1 and "minute" or "minutes" ) + ", "
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string += str(seconds) + " " + (seconds == 1 and "second" or "seconds" )
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return string;
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print "The system uptime is:", uptime()
One interesting thing about this script is its emulation of the C ternary operator using Python's short-circuited "and" operator. Notice this bit:
PYTHON:
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(days == 1 and "day" or "days" )
Python doesn't have the C-style ternary operator:
C++:
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(days == 1 ? "day" : "days")
So the short-circuited "and" is a decent alternative. Instead of ignorantly printing "1 days", this code will actually print "1 day" and "2 days" like it should.
