pythonos结果
❶ python 使用 os.system() 时没有返回正常的结果,返回了256 ubuntu16.04系统下 python版本 2.7.11
os.system方法返回的是系统程序执行后的返回值。这里256也许是有256项。
要获得标准输出stdout需要用子进程模块subprocess,这是python3.x的做法。
2.7也许有类似吧.
❷ python os模块怎么使用
常用方法:
1. os.name——判断现在正在实用的平台,Windows 返回 ‘nt'; linux 返回’posix'。
2. os.getcwd()——得到当前工作的目录。
3. os.listdir()——指定所有目录下所有的文件和目录名。
例:
❸ python调用OS.system结束进程问题
os.system是执行命令,是否打印取决于命令是否有返回
如果你想不让其打印 可以在命令中做手脚如: os.system('taskkill /IM dllhost.exe > NUL')
❹ python里面怎么将os.system的执行结果返回到变量
os.system(command)将返回系统执行command的结果,0为无错误。将其直接赋值给变量即可。
例如在Linux系统下执行输出文件列表命令ls:
a = os.system('ls')
a的值为0,表明执行命令无错误。
{在Windows系统下,输出文件列表命令为dir。}
❺ python3中,用os.system运行一个python2的程序(该程序调用一些模块),结果好像是调用了python3模块出错
环境变量里面设置的python3的路径,所以os调用的时候启动的python3,具体可以在命令行输入python --version看下版本号
❻ windows python3 怎样获得os的返回值
解决:查阅了文档发现os.system()的返回为:
On Unix, the return value is the exit status of the process encoded in the format specified for wait().
而os.wait()的返回为:
a 16-bit number, whose low byte is the signal number that killed the process, and whose high byte is the exit status (if the signal number
is zero);
os.system的返回值并不是执行程序的返回结果。而是一个16位的数,它的高位才是返回码。也就是说os.system()返回256即 0×0100,返回码应该是其高位0×01即1。所以要获取程序运行退出的值(比如C的main函数中的return 0),需要处理一下。
ret = os.system('./a.out')
ret >>= 8
这样才能获取到正确的返回值。另外还要注意:python获取到的值是无符号整数,所以返回负值的时候,打印出来是很大的正值。比如返回-1,python 会获取到255,-2则254,以此类推。所以最好就判断是否为0就可以了,实在要判断自己写的c程序返回值,建议返回0,1,2,3等值,出错返回 -1。
另外,我遇到一次明明处理好了返回值,c程序调试信息提示也该返回值0了,结果python获取到的是 -1,而且无论c程序返回多少,python都获取-1。后来排查c程序的问题,发现原来是因为我这个python程序本身是由另一个C程序调用的,而调 用它的那个C程序中将SIGCLD信号忽略了(这表明python是根据子进程退出时产生的信号来获取返回值的),我将那个C程序的SIGCLD绑定到函 数,即使那个函数什么也不做,python也能获取到正确的返回值了。
/**********************************************************************************************************************/
linux命令执行后无论成功与否都有一个返回值:
如果为 0,则表示命令执行成功,其它值则表示错误,具体的错误码含义如下:
"OS error code 1: Operation not permitted"
"OS error code 2: No such file or directory"
"OS error code 3: No such process"
"OS error code 4: Interrupted system call"
"OS error code 5: Input/output error"
"OS error code 6: No such device or address"
"OS error code 7: Argument list too long"
"OS error code 8: Exec format error"
"OS error code 9: Bad file descriptor"
"OS error code 10: No child processes"
"OS error code 11: Resource temporarily unavailable"
"OS error code 12: Cannot allocate memory"
"OS error code 13: Permission denied"
"OS error code 14: Bad address"
"OS error code 15: Block device required"
"OS error code 16: Device or resource busy"
"OS error code 17: File exists"
"OS error code 18: Invalid cross-device link"
"OS error code 19: No such device"
"OS error code 20: Not a directory"
"OS error code 21: Is a directory"
"OS error code 22: Invalid argument"
"OS error code 23: Too many open files in system"
"OS error code 24: Too many open files"
"OS error code 25: Inappropriate ioctl for device"
"OS error code 26: Text file busy"
"OS error code 27: File too large"
"OS error code 28: No space left on device"
"OS error code 29: Illegal seek"
"OS error code 30: Read-only file system"
"OS error code 31: Too many links"
"OS error code 32: Broken pipe"
"OS error code 33: Numerical argument out of domain"
"OS error code 34: Numerical result out of range"
"OS error code 35: Resource deadlock avoided"
"OS error code 36: File name too long"
"OS error code 37: No locks available"
"OS error code 38: Function not implemented"
"OS error code 39: Directory not empty"
"OS error code 40: Too many levels of symbolic links"
"OS error code 42: No message of desired type"
"OS error code 43: Identifier removed"
"OS error code 44: Channel number out of range"
"OS error code 45: Level 2 not synchronized"
"OS error code 46: Level 3 halted"
"OS error code 47: Level 3 reset"
"OS error code 48: Link number out of range"
"OS error code 49: Protocol driver not attached"
"OS error code 50: No CSI structure available"
"OS error code 51: Level 2 halted"
"OS error code 52: Invalid exchange"
"OS error code 53: Invalid request descriptor"
"OS error code 54: Exchange full"
"OS error code 55: No anode"
"OS error code 56: Invalid request code"
"OS error code 57: Invalid slot"
"OS error code 59: Bad font file format"
"OS error code 60: Device not a stream"
"OS error code 61: No data available"
"OS error code 62: Timer expired"
"OS error code 63: Out of streams resources"
"OS error code 64: Machine is not on the network"
"OS error code 65: Package not installed"
"OS error code 66: Object is remote"
"OS error code 67: Link has been severed"
"OS error code 68: Advertise error"
"OS error code 69: Srmount error"
"OS error code 70: Communication error on send"
"OS error code 71: Protocol error"
"OS error code 72: Multihop attempted"
"OS error code 73: RFS specific error"
"OS error code 74: Bad message"
"OS error code 75: Value too large for defined data type"
"OS error code 76: Name not unique on network"
"OS error code 77: File descriptor in bad state"
"OS error code 78: Remote address changed"
"OS error code 79: Can not access a needed shared library"
"OS error code 80: Accessing a corrupted shared library"
"OS error code 81: .lib section in a.out corrupted"
"OS error code 82: Attempting to link in too many shared libraries"
"OS error code 83: Cannot exec a shared library directly"
"OS error code 84: Invalid or incomplete multibyte or wide character"
"OS error code 85: Interrupted system call should be restarted"
"OS error code 86: Streams pipe error"
"OS error code 87: Too many users"
"OS error code 88: Socket operation on non-socket"
"OS error code 89: Destination address required"
"OS error code 90: Message too long"
"OS error code 91: Protocol wrong type for socket"
"OS error code 92: Protocol not available"
"OS error code 93: Protocol not supported"
"OS error code 94: Socket type not supported"
"OS error code 95: Operation not supported"
"OS error code 96: Protocol family not supported"
"OS error code 97: Address family not supported by protocol"
"OS error code 98: Address already in use"
"OS error code 99: Cannot assign requested address"
"OS error code 100: Network is down"
"OS error code 101: Network is unreachable"
"OS error code 102: Network dropped connection on reset"
"OS error code 103: Software caused connection abort"
"OS error code 104: Connection reset by peer"
"OS error code 105: No buffer space available"
"OS error code 106: Transport endpoint is already connected"
"OS error code 107: Transport endpoint is not connected"
"OS error code 108: Cannot send after transport endpoint shutdown"
"OS error code 109: Too many references: cannot splice"
"OS error code 110: Connection timed out"
"OS error code 111: Connection refused"
"OS error code 112: Host is down"
"OS error code 113: No route to host"
"OS error code 114: Operation already in progress"
"OS error code 115: Operation now in progress"
"OS error code 116: Stale NFS file handle"
"OS error code 117: Structure needs cleaning"
"OS error code 118: Not a XENIX named type file"
"OS error code 119: No XENIX semaphores available"
"OS error code 120: Is a named type file"
"OS error code 121: Remote I/O error"
"OS error code 122: Disk quota exceeded"
"OS error code 123: No medium found"
"OS error code 124: Wrong medium type"
"OS error code 125: Operation canceled"
"OS error code 126: Required key not available"
"OS error code 127: Key has expired"
"OS error code 128: Key has been revoked"
"OS error code 129: Key was rejected by service"
"OS error code 130: Owner died"
"OS error code 131: State not recoverable"
❼ python,os.popen 打包后出现问题
你打包成exe后,命令行应该是pyinstller -Fw xxx.py
你加上了w参数也就是把console设置成了flase;那么os.popen()或者subprocess.popen()执行的时候没有载体,你只有把console设置成true,也就是命令改为pyinstaller -F xxx.py,这样你的os.popen()可执行,也能获得返回值。
❽ python函数里调用os模块中的内容结果显示未定义
你的问题很奇怪,我的都可以通过
❾ python调用另外一个python程序的结果
os.system只是运行,不返回结果。
用commands
import commands
txt = commands.getoutput('ls -al')
❿ python模块os里面os.system命令返回什么
linux命令都是返回0代表成果,这是一个习惯,基本没有人用返回值0代表命令失败.
所以 os.system(命令) 如果返回为0则带便命令执行成功了.
具体返回其他数值代表什么意思,就要看具体命令是什么了.比如最常用的 ls 命令, 有三个返回值:
0 代表成功
1 代表小问题
2 代表大问题