我想在python中创建一个rdiff-backup包装器程序，用于将windows机器备份到linux服务器。
我想在包装程序中处理rdiff-backup的输出。但是当使用子进程模块执行rdiff-backup并将stdout和stderr传递给包装器时，stdout总是最终成为管道的末尾。
当使用subprocess而不管道时，stdout会在控制台中以正确的顺序打印stderr。
在本地使用rdiff-backup并且不使用ssh管道时，我也注意到了什么，stdout和stderr的顺序正确。 Rdiff-backup还使用subprocess.popen打开ssh会话并将数据传输到服务器。我怀疑由于某种原因，stdout会被阻止，直到ssh会话结束。
这是我的代码，这是真正的程序使用线程来监听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
答案 0 :(得分：1)
我终于能够解决问题了
当它被传送到另一个程序时，Rdiff-backup缓冲了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，以便在使用Windows 7构建时使其工作
Py2exe - win32api.pyc ImportError DLL load failed
这是来自rdiff-backup版本的最终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
})
答案 1 :(得分：0)
尝试为stdout和stderr使用单独的管道。首先阅读stdout行，然后阅读stderr中的行。