我想在python中创建一个rdiff-backup包装程序，将Windows计算机备份到linux服务器。
我想在包装程序中处理rdiff-backup的输出。但是，当使用子流程模块执行rdiff-backup并将stdout和stderr用管道传递到包装器时，stdout总是以管道的末端结束。
使用不带管道的子流程时，stdout和stderr会在控制台中以正确的顺序打印。
我还注意到，在本地使用rdiff-backup而不使用ssh管道时，stdout和stderr的顺序正确。 Rdiff-backup也使用subprocess.popen打开ssh会话并将数据通过管道传输到服务器。我怀疑出于某种原因stdout会被阻塞，直到ssh会话关闭。
这是我的代码，这是真实程序使用线程侦听stdout的简化版本：
import sys
import subprocess
class Rdiffbackup(object):
def __init__(self):
#self.io_q = Queue()
self.exe = 'F:\\workspace\\pysubprocess\\bin\\rdiff-backup\\rdiff-backup.exe'
self.verbosity = '-v5'
self.ssh_exe = './bin/openssh/bin/ssh'
self.quiet = '-q'
self.compression = '-C'
self.port = '-p 5555'
self.key = '-i ./keys/rdiffbackup'
self.options = '-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
self.remote_schema = self.ssh_exe + ' ' + self.quiet + ' ' + self.compression + ' ' + self.port + ' ' + self.key + ' ' + self.options + ' %s rdiff-backup --server'
def start(self,source,dest):
with subprocess.Popen([self.exe,self.verbosity,'--remote-schema',self.remote_schema,source,dest],stdout=subprocess.PIPE,stderr=subprocess.STDOUT) as self.proc:
for line in self.proc.stdout:
sys.stdout.write(line.decode("utf-8"))
if __name__ == '__main__':
rdb = Rdiffbackup()
source = "C:/Users/vdrmrt/Desktop/data"
dest = "vdrmrt@hostname::backup"
rdb.start(source,dest)
输出：
-----------------------------------------------------------------
Detected abilities for source (read only) file system:
Access control lists Off
Extended attributes Off
Windows access control lists On
Case sensitivity Off
Escape DOS devices Off
Escape trailing spaces Off
Mac OS X style resource forks Off
Mac OS X Finder information Off
-----------------------------------------------------------------
Unable to import win32security module. Windows ACLs
not supported by filesystem at backup/rdiff-backup-data/rdiff-backup.tmp.0
escape_dos_devices not required by filesystem at backup/rdiff-backup-data/rdiff-backup.tmp.0
-----------------------------------------------------------------
Detected abilities for destination (read/write) file system:
Ownership changing Off
Hard linking On
fsync() directories On
Directory inc permissions On
High-bit permissions On
Symlink permissions Off
Extended filenames On
Windows reserved filenames Off
Access control lists On
Extended attributes On
Windows access control lists Off
Case sensitivity On
Escape DOS devices Off
Escape trailing spaces Off
Mac OS X style resource forks Off
Mac OS X Finder information Off
-----------------------------------------------------------------
Backup: must_escape_dos_devices = 0
Using rdiff-backup version 1.2.8
Executing ./bin/openssh/bin/ssh -q -C -p 5555 -i ./keys/rdiffbackup -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null vdrmrt@hostname rdiff-backup --server
Hardlinks disabled by default on Windows
Unable to import module xattr.
Extended attributes not supported on filesystem at C:/Users/vdrmrt/Desktop/data
Unable to import module posix1e from pylibacl package.
POSIX ACLs not supported on filesystem at C:/Users/vdrmrt/Desktop/data
escape_dos_devices not required by filesystem at C:/Users/vdrmrt/Desktop/data
Symbolic links excluded by default on Windows
Starting increment operation C:/Users/vdrmrt/Desktop/data to backup
正确的输出：
Using rdiff-backup version 1.2.8
Executing ./bin/openssh/bin/ssh -q -C -p 5555 -i ./keys/rdiffbackup -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null vdrmrt@hostname rdiff-backup --server
Hardlinks disabled by default on Windows
Unable to import module xattr.
Extended attributes not supported on filesystem at C:/Users/vdrmrt/Desktop/data
Unable to import module posix1e from pylibacl package.
POSIX ACLs not supported on filesystem at C:/Users/vdrmrt/Desktop/data
escape_dos_devices not required by filesystem at C:/Users/vdrmrt/Desktop/data
-----------------------------------------------------------------
Detected abilities for source (read only) file system:
Access control lists Off
Extended attributes Off
Windows access control lists On
Case sensitivity Off
Escape DOS devices Off
Escape trailing spaces Off
Mac OS X style resource forks Off
Mac OS X Finder information Off
-----------------------------------------------------------------
Unable to import win32security module. Windows ACLs
not supported by filesystem at backup/rdiff-backup-data/rdiff-backup.tmp.0
escape_dos_devices not required by filesystem at backup/rdiff-backup-data/rdiff-backup.tmp.0
-----------------------------------------------------------------
Detected abilities for destination (read/write) file system:
Ownership changing Off
Hard linking On
fsync() directories On
Directory inc permissions On
High-bit permissions On
Symlink permissions Off
Extended filenames On
Windows reserved filenames Off
Access control lists On
Extended attributes On
Windows access control lists Off
Case sensitivity On
Escape DOS devices Off
Escape trailing spaces Off
Mac OS X style resource forks Off
Mac OS X Finder information Off
-----------------------------------------------------------------
Backup: must_escape_dos_devices = 0
Symbolic links excluded by default on Windows
Starting increment operation C:/Users/vdrmrt/Desktop/data to backup
最佳答案
我终于能够解决问题。
当Rdiff备份通过管道传送到另一个程序时，它会缓冲stdout和stderr。
解决方案是使用额外的py2exe选项重建rdiff-backup：'unbuffered'：True
我还必须添加一个额外的选项，以使其在使用Windows 7构建时可以正常工作。
Py2exe - win32api.pyc ImportError DLL load failed
这是来自rdiff-backup构建的最终setup.py的片段。
if '--single-file' in sys.argv[1:]:
sys.argv.remove('--single-file')
extra_options.update({
'options': {'py2exe': {'bundle_files': 1,
'unbuffered': True,
'dll_excludes': [ "mswsock.dll", "powrprof.dll" ]}},
'zipfile': None
})