将终端命令转换为python脚本

Question

如何将此终端命令转换为python？ 这是我尝试过的代码，我需要一些帮助。 我要传入的值是<| grep“http”>包括文件本身，但是传入多个值时出错。

终端命令： swfdump -a /home/cfc/swf/swf/flash2.swf | grep 'http' swfdump -a /home/cfc/swf/swf/flash2.swf | grep 'http'

尝试1： dump = Popen(["swfdump", "-a", filename, "|", "grep", "'http'"])

尝试2： dump = check_output(["swfdump", "-a", filename , "| grep 'http'"])

错误：

试试1：

Only one file allowed. You supplied at least two. (/home/cfc/swf/swf/flash2.swf and |)
Only one file allowed. You supplied at least two. (| and grep)
Only one file allowed. You supplied at least two. (grep and 'http')
Couldn't open 'http': No such file or directory
Only one file allowed. You supplied at least two. (/home/cfc/swf/swf/flash2.swf and |)
Only one file allowed. You supplied at least two. (| and grep)
Only one file allowed. You supplied at least two. (grep and 'http')
Couldn't open 'http': No such file or directory

试试2：

Only one file allowed. You supplied at least two. (/home/cfc/swf/swf/flash2.swf and | grep 'http')
Couldn't open | grep 'http': No such file or directory
Traceback (most recent call last):
File "./SWFFile.py", line 62, in <module>
main()
File "./SWFFile.py", line 61, in main
trid()
File "./SWFFile.py", line 34, in trid
swfDump()
File "./SWFFile.py", line 48, in swfDump
dump = check_output(["swfdump", "-a", filename , "| grep 'http'"] )
File "/usr/lib/python2.7/subprocess.py", line 573, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '['swfdump', '-a', '/home/cfc/swf/swf/flash2.swf', "| grep 'http'"]' returned non-zero exit status 1

Answer 1

管道命令"|" 是一个shell构造，对python没有意义。 当您使用列表执行Popen并且没有shell=True ，将绕过shell，并且管道符号将作为命令行参数传递给正在执行的程序。 困惑的程序会回报错误。

您可以通过将命令转换为字符串或让python将命令转换为字符串来运行shell：

dump = Popen("swfdump -a {} | grep 'http'".format(filename),
     shell=True)

dump = Popen(subprocess.list2cmdline(
    ["swfdump", "-a", filename, "|", "grep", "'http'"]),
    shell=True)

或者，在python本身进行搜索

proc = Popen(["swfdump", "-a", filename], stdout=subprocess.PIPE)
for line in proc.stdout:
    if 'http' in line:
        print(line.strip())
proc.wait()

Answer 2

如果您对从Python运行大量外部命令感兴趣，那么使用sh模块的结果更简单，更易读：

from sh import swfdump, grep

grep(swfdump('-a', '/home/cfc/swf/swf/flash2.swf'), 'http')

请注意，使用Python比使用外部命令更好地完成grepping：

from sh import swfdump

for line in swfdump('-a', '/home/cfc/swf/swf/flash2.swf').split('\n'):
    if 'http' in line:
        print(line)