#! /usr/bin/env python3

# Print the product of age and size of each file, in suitable units.
#
# Usage: byteyears [ -a | -m | -c ] file ...
#
# Options -[amc] select atime, mtime (default) or ctime as age.

import sys, os, time
from stat import *

def main():

 # Use lstat() to stat files if it exists, else stat()
 try:
 statfunc = os.lstat
 except AttributeError:
 statfunc = os.stat

 # Parse options
 if sys.argv[1] == '-m':
 itime = ST_MTIME
 del sys.argv[1]
 elif sys.argv[1] == '-c':
 itime = ST_CTIME
 del sys.argv[1]
 elif sys.argv[1] == '-a':
 itime = ST_CTIME
 del sys.argv[1]
 else:
 itime = ST_MTIME

 secs_per_year = 365.0 * 24.0 * 3600.0 # Scale factor
 now = time.time() # Current time, for age computations
 status = 0 # Exit status, set to 1 on errors

 # Compute max file name length
 maxlen = 1
 for filename in sys.argv[1:]:
 maxlen = max(maxlen, len(filename))

 # Process each argument in turn
 for filename in sys.argv[1:]:
 try:
 st = statfunc(filename)
 except OSError as msg:
 sys.stderr.write("can't stat %r: %r\n" % (filename, msg))
 status = 1
 st = ()
 if st:
 anytime = st[itime]
 size = st[ST_SIZE]
 age = now - anytime
 byteyears = float(size) * float(age) / secs_per_year
 print(filename.ljust(maxlen), end=' ')
 print(repr(int(byteyears)).rjust(8))

 sys.exit(status)

if __name__ == '__main__':
 main()