reformat vmstat

vmstat.py

#!/usr/bin/env python

import sys
import subprocess

def main():
    if len(sys.argv) > 1:
        time = sys.argv[1]
    else:
        time = "1"
    vmstat = subprocess.Popen(['/usr/bin/vmstat', time],
                                stdout=subprocess.PIPE, 
                                stderr=subprocess.STDOUT)

    line = vmstat.stdout.readline()
    max_widths = [2, 2, 6, 6, 6, 6, 4, 4, 5, 5, 4, 4, 2, 2, 2, 2]
    headers = ["procs", "memory", "swap", "io", "system", "cpu"]
    header_columns = [ [0, 1], [2, 3, 4, 5], [6 , 7], [8, 9], [10, 11], [12, 13, 14, 15] ]
    while line:
        line = line.split()
        
        if line[0] == "procs":
            header_width = [sum(max_widths[i] for i in cols) + len(cols) - 1 for cols in header_columns]
            fstr = " ".join(["{:-^%ds}"%w for w in header_width]) 
            print fstr.format(*headers)
        else:
            max_widths = [ max(new, old) for new,old in zip(map(len, line), max_widths) ]
            fstr = " ".join(["{: >%ds}"%w for w in max_widths]) 
            print fstr.format(*line)
        line = vmstat.stdout.readline()

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        pass