如何將subprocess.call（）輸出推送到終端和文件？

Question

我有subprocess.call(["ddrescue", in_file_path, out_file_path], stdout=drclog) 。 我希望在運行時在終端中顯示ddrescue並將輸出寫入文件drclog。 我試過使用subprocess.call(["ddrescue", in_file_path, out_file_path], stdout=drclog, shell=True) ，但這給了我ddrescue輸入錯誤。

Answer 1

如果ddrescue的stdout / stderr重定向到管道時ddrescue不會更改其輸出，則可以使用tee實用程序在終端上顯示輸出並將其保存到文件中：

$ ddrescue input_path output_path ddrescue_logfile |& tee logfile

如果確實如此，那么您可以嘗試使用script實用程序提供一個偽tty：

$ script -c 'ddrescue input_path output_path ddrescue_logfile' -q logfile

如果它直接寫到終端，則可以使用screen捕獲輸出：

$ screen -L -- ddrescue input_path output_path ddrescue_logfile

默認情況下，輸出保存在screenlog.0文件中。

---

要在Python中模擬基於tee的命令而不調用tee實用程序，請執行以下操作：

#!/usr/bin/env python3
import shlex
import sys
from subprocess import Popen, PIPE, STDOUT

command = 'ddrescue input_path output_path ddrescue_logfile'
with Popen(shlex.split(command), stdout=PIPE, stderr=STDOUT, bufsize=1) as p:
    with open('logfile', 'wb') as logfile:
        for line in p.stdout:
            logfile.write(line)
            sys.stdout.buffer.write(line)
            sys.stdout.buffer.flush()

要使用shell=True在Python中調用基於tee的命令：

#!/usr/bin/env python
from pipes import quote
from subprocess import call

files = input_path, output_path, ddrescue_logfile
rc = call('ddrescue {} |  tee -a drclog'.format(' '.join(map(quote, files))),
          shell=True)

要模擬基於script的命令：

#!/usr/bin/env python3
import os
import shlex
import pty

logfile = open('logfile', 'wb')
def read(fd):
    data = os.read(fd, 1024) # doesn't block, it may return less
    logfile.write(data) # it can block but usually not for long
    return data
command = 'ddrescue input_path output_path ddrescue_logfile'
status = pty.spawn(shlex.split(command), read)
logfile.close()

要在Python中調用screen命令：

#!/usr/bin/env python3
import os
import shlex
from subprocess import check_call

screen_cmd = 'screen -L -- ddrescue input_path output_path ddrescue_logfile'
check_call(shlex.split(screen_cmd))
os.replace('screenlog.0', 'logfile')

Answer 2

對我subprocess.call(["ddrescue $0 $1 | tee -a drclog", in_file_path, out_file_path], shell=True)的解決方案是subprocess.call(["ddrescue $0 $1 | tee -a drclog", in_file_path, out_file_path], shell=True) 。