shell-proc 1.2.2

Continuous shell process

Install

pip install shell_proc

Run

Run a series of commands with results.

from shell_proc import Shell

with Shell() as sh:
    sh('cd ..')
    if sh.is_windows():
        cmd = sh('dir')
    else:
        cmd = sh('ls')

    # cmd (Command) Attributes: cmd, exit_code, stdout, stderr
    print(cmd.stdout)

Run a series of terminal commands.

import sys
from shell_proc import Shell

with Shell(stdout=sys.stdout, stderr=sys.stderr) as sh:
    sh.run('mkdir storage')
    sh('cd storage')  # Same as sh.run()
    sh('echo Hello World! > hello.txt')

    if sh.is_windows():
        sh('python -m venv ./winvenv')
        sh('call ./winvenv/Scripts/activate.bat')
    else:
        pwd = sh('pwd')
        sh('cd ~')
        sh('python3 -m venv ./lxvenv')
        sh('source ./lxvenv/bin/activate')
        sh('cd {}'.format(pwd.stdout))
    sh('pip install requests')
    sh('pip list')

table = '|{:_<20}|{:_<20}|{:_<20}|{:_<50}|'
print(table.format('', '', '', '').replace('|', '_'))
print(table.format("Exit Code", "Has Error", "Has Ouput", "Command").replace('_', ' '))
print(table.format('', '', '', ''))
for cmd in sh.history:
    print(table.format(cmd.exit_code, cmd.has_error(), cmd.has_output(), cmd.cmd).replace('_', ' '))
print(table.format('', '', '', '').replace('|', '_'))

Run without blocking every command

import sys
import time
from shell_proc import Shell

with Shell(stdout=sys.stdout, stderr=sys.stderr, blocking=False, wait_on_exit=True) as sh:
    sh.run('mkdir storage')
    sh('cd storage')  # Same as sh.run()
    sh('echo Hello World! > hello.txt')

    if sh.is_windows():
        sh('python -m venv ./winvenv')
        sh('call ./winvenv/Scripts/activate.bat')
    else:
        pwd = sh('pwd')
        sh('cd ~')
        sh('python3 -m venv ./lxvenv')
        sh('source ./lxvenv/bin/activate')
        sh('cd {}'.format(pwd.stdout))
    sh('pip install requests')
    sh('pip list')
    print('---------- At exit (shows non-blocking until exit) ----------')

time.sleep(1)
print('1 Second has passed', 'Running:', sh.current_command)
time.sleep(1)
print('2 Seconds have passed', 'Running:', sh.current_command)
time.sleep(1)
print('3 Seconds have passed', 'Running:', sh.current_command)

sh.wait()  # Wait for all commands to finish

Manually call commands and check results.

import io
import sys
from shell_proc import Shell

# Initialize and run tasks
sh = Shell('mkdir storage',
           'cd storage',
           'echo Hello World! > hello.txt',
           stderr=io.StringIO())

# Manually run tasks
if sh.is_windows():
    sh('python -m venv ./winvenv')
    sh('call ./winvenv/Scripts/activate.bat')
else:
    pwd = sh('pwd')
    sh('cd ~')
    sh('python3 -m venv ./lxvenv')
    sh('source ./lxvenv/bin/activate')
    sh('cd {}'.format(pwd.stdout))

# Not exactly success. If True no output was printed to stderr. Stderr could also be warning like need to update pip
results = sh.run('pip install requests')
print("***** Successful install: ", results.exit_code == 0)
if results.exit_code != 0:
    sh.stderr.seek(0)  # Move to start of io.StringIO()
    err = sh.stderr.read()  # All text collected into stderr from subprocess stderr
    print(err, file=sys.stderr)
    # sh.print_stderr()  # Also available

sh.stdout = io.StringIO()  # Start saving output for new tasks
results = sh('pip list')
print('***** Output Printed\n', results.stdout)

sh('pip -V')
print('pip -V =>', sh.last_command.stdout)

print('All collected stdout')
sh.stdout.seek(0)  # Move to start of io.StringIO()
print(sh.stdout.read(), end='', flush=True)  # Print all read data

# Should close when finished to stop threads from reading stdout and stderr subprocess.PIPE
# (will close automatically eventually)
sh.close()

io.StringIO() Help

Below are several functions to read data from stdout and io.StringIO()

def read_io(fp):
    """Return all of the human readable text from the io object."""
    try:
        if fp.seekable():
            fp.seek(0)
        out = fp.read()
        if not isinstance(out, str):
            out = out.decode('utf-8')
        return out
    except:
        return ''

def clear_io(fp):
    """Try to clear the stdout"""
    text = read_io(fp)
    try:
        fp.truncate(0)
    except:
        pass
    return text

def print_io(fp, end='\n', file=None, flush=True):
    """Print and clear the collected io."""
    if file is None:
        file = sys.stdout
    print(clear_io(fp), file=file, flush=True)

Run Python

Added support to call python in a subprocess

from shell_proc import Shell

with Shell(python_call='python3') as sh:
    sh.python('-c',
              'import os',
              'print("My PID:", os.getpid())')

Run Parallel

Added support to run parallel subprocesses

import sys
import time
from shell_proc import Shell, python_args

with Shell(stdout=sys.stdout, stderr=sys.stderr) as sh:
    p = sh.parallel(*(python_args('-c',
                'import os',
                'import time',
                "print('My ID:', {id}, 'My PID:', os.getpid(), time.time())".format(id=i)) for i in range(10)))
    sh.wait()  # or p.wait()
    print('finished parallel')
    time.sleep(1)

    tasks = []
    for i in range(10):
        if i == 3:
            t = python_args('-c',
                'import os',
                'import time',
                'time.sleep(1)',
                "print('My ID:', {id}, 'My PID:', os.getpid(), time.time())".format(id=i))
        else:
            t = python_args('-c',
                'import os',
                'import time',
                "print('My ID:', {id}, 'My PID:', os.getpid(), time.time())".format(id=i))
        tasks.append(t)
    p = sh.parallel(*tasks)
    p.wait()
    print('finished parallel')
    time.sleep(1)

    with sh.parallel() as p:
        for i in range(10):
            if i == 3:
                p.python('-c',
                         'import os',
                         'import time',
                         'time.sleep(1)',
                         "print('My ID:', {id}, 'My PID:', os.getpid(), time.time())".format(id=i))
            else:
                p.python('-c',
                         'import os',
                         'import time',
                         "print('My ID:', {id}, 'My PID:', os.getpid(), time.time())".format(id=i))
        # p.wait() on exit context
    print('finished parallel')

Use Pipe

The pipe operator can be used with Command objects to take a completed command stdout and submit the text into a new commands stdin.

import sys
from shell_proc import Shell, ShellExit, shell_args

with Shell(stdout=sys.stdout, stderr=sys.stderr) as sh:
    # One step
    results = sh('dir') | 'find "run"'  # Hard to tell where find output starts

    # Two Steps
    cmd = sh('dir')
    results = cmd | 'find "run"'