关于python调用shell命令

[moxiaomomo]

    val = "test_res"
    os.environ['var'] = val
    os.popen('echo -ne $var')

运行的结果为 -ne test_res

-ne是用来限制不换行刷新输出的，不应该直接被echo啊。
请问echo命令下选项-ne为什么没有被正确引用呢？

[moxiaomomo]

不好意思，写错了...是os.system

    val = "test_res"
    os.environ['var'] = val
    os.system('echo -ne $var')

[moxiaomomo]

换用了subprocess.call(['echo', '-n', '-e', val]) 就可以了。os.system还是不知道怎么解决。

[livesguan]

用os.system(cmd) 取不了返回值。

[livesguan]

这还有其它的方法 1.用os.popen(cmd) 要得到命令的输出内容，只需再调用下read()或readlines()等 如a=os.popen(cmd).read() 使用 a.rstrip() 进行去除换行符“\n" 2.用 commands 模块。其实也是对popen的封装。 3.subprocess.Popen

[szqh97]

http://stackoverflow.com/questions/905221/os-system-execute-command-under-which-linux-shell os.system() just calls the system() system call ("man 3 system"). On most *nixes this means you get /bin/sh. Note that export VAR=val is technically not standard syntax (though bash understands it, and I think ksh does too). It will not work on systems where /bin/sh is actually the Bourne shell. On those systems you need to export and set as separate commands. (This will work with bash too.) 也只有这样才能讲通了， 在/bin/sh下 echo 是没有 -e这项的，