minte9

LearnRemember

Pipes

 
# Pipe object:
#
# Programs launched from the shell ...
# can also be launch from Python using pipe object.
#
# The return value is an object that behaves like a file.

import os

cmd = 'ls -l'
fp = os.popen(cmd)
res = fp.read()
print(res)
    # -rw-rw-r-- 1 catalin catalin 16384 iul 15 12:35 images_db
    # drwxr-xr-x 3 catalin catalin  4096 iul 13 09:35 layouts
    # drwxr-xr-x 5 catalin catalin  4096 iun  4  2020 library

stat = fp.close()
print(stat) # None (no errors)

Check

 
# Using pipe ...
# you can use md5sum ...
# to check if two files have the same content.

import os

DIR = os.path.dirname(os.path.realpath(__file__))

file1 = DIR + "/data/01.txt"
f = open(file1, "w")
f.write("1234567890")
f.close()

file2 = DIR + "/data/02.txt"
f = open(file2, "w")
f.write("1234567890")
f.close()

def md5sum (filename):
    cmd = 'md5sum ' + filename
    fp = os.popen(cmd)
    res = fp.read() 
    print(res) 
        # 5a92d5b6e2303c7fea60297d2c985713  01.txt
    md5sum = res.replace(filename, '')
    stat = fp.close()
    return md5sum

assert md5sum(file1) == md5sum(file2) # pass