fs_stats.py

#!/usr/bin/env python3

"""
Display various file statistics for each directory.
"""

import sys
import os
import stat
from time import strftime, localtime


class FileStats:
    
    def __init__(self):
        self.min_mtime = None
        self.max_mtime = None
        self.min_ctime = None
        self.max_ctime = None
        self.min_atime = None
        self.max_atime = None                
        self.tot_blocks = 0
        self.tot_inodes = 0

    def add(self, stat_data):
        mtime = stat_data.st_mtime
        ctime = stat_data.st_ctime
        atime = stat_data.st_atime
        self.min_mtime = self._min(self.min_mtime, mtime)
        self.max_mtime = self._max(self.max_mtime, mtime)
        self.min_ctime = self._min(self.min_ctime, ctime)
        self.max_ctime = self._max(self.max_ctime, ctime)
        self.min_atime = self._min(self.min_atime, atime)
        self.max_atime = self._max(self.max_atime, atime)
        self.tot_blocks += stat_data.st_blocks
        self.tot_inodes += 1
        
    def update(self, other):
        self.min_mtime = self._min(self.min_mtime, other.min_mtime)
        self.max_mtime = self._max(self.max_mtime, other.max_mtime)
        self.min_ctime = self._min(self.min_ctime, other.min_ctime)
        self.max_ctime = self._max(self.max_ctime, other.max_ctime)
        self.min_atime = self._min(self.min_atime, other.min_atime)
        self.max_atime = self._max(self.max_atime, other.max_atime)
        self.tot_blocks += other.tot_blocks
        self.tot_inodes += other.tot_inodes

    def _max(self, a, b):
        return self._func(a, b, max)

    def _min(self, a, b):
        return self._func(a, b, min)
    
    def _func(self, a, b, f):
        if a is None:
            return b
        elif b is None:
            return a
        else:
            return f(a, b)
            
    def __str__(self):
        
        fields = [
            ('min_mtime', self._time_format(self.min_mtime)),
            ('max_mtime', self._time_format(self.max_mtime)),
            ('min_ctime', self._time_format(self.min_ctime)),
            ('max_ctime', self._time_format(self.max_ctime)),
            ('min_atime', self._time_format(self.min_atime)),
            ('max_atime', self._time_format(self.max_atime)),
            ('blocks', self.tot_blocks),
            ('inodes', self.tot_inodes),
        ]
        return ' '.join(f'{k}={v}' for k, v in fields)
                            
    def _time_format(self, timeval):
        if timeval is None:
            return 'None'
        else:
            return strftime('%Y-%m-%d.%H:%M:%S', localtime(timeval))
    
    
def scan(path, depth=0):
    stats = FileStats()
    try:
        els = os.listdir(path)
    except OSError as exc:
        sys.stderr.write(f"{exc}\n")
        return stats
    for el in els:
        elp = os.path.join(path, el)
        try:
            stat_data = os.lstat(elp)
        except OSError as exc:
            sys.stderr.write(f"{exc}\n")
            continue
        if stat.S_ISDIR(stat_data.st_mode):
            stats_sub = scan(elp, depth=(depth + 1))
            stats.update(stats_sub)
        else:
            stats.add(stat_data)
    stat_data = os.lstat(path)
    stats.add(stat_data)
    print(f'{stats} depth={depth} {path}')
    return stats
    

def main():
    try:
        path, = sys.argv[1:]
    except ValueError:
        sys.stderr.write("starting path needed as command line argument\n")
        sys.exit(1)
    scan(path)
    

if __name__ == '__main__':
    main()