I made 2 classes:
Input which implements read method, and
Output which implements write method
I am trying to call a shell command and capture the input and output. This is my code:
import subprocess
command = "date"
output = Output()
input = Input()
process = subprocess.Popen(command,
stdout=output, stdin=input, shell=False)
but when I check the output instance it says that it contains no data.
Technically, those class instances are probably invalid parameters, unless they inherit from a file object.
According to the documentation (emphasis mine):
stdin, stdout and stderr specify the executed program’s standard input, standard output and standard error file handles, respectively. Valid values are PIPE, DEVNULL, an existing file descriptor (a positive integer), an existing file object, and None. PIPE indicates that a new pipe to the child should be created. DEVNULL indicates that the special file os.devnull will be used. With the default settings of None, no redirection will occur; the child’s file handles will be inherited from the parent. Additionally, stderr can be STDOUT, which indicates that the stderr data from the applications should be captured into the same file handle as for stdout.
PIPE. Then you should be able to just use process.stdout.read() and process.stdin.write(). But keep in mind that the operating system's buffers are not infinite.