如何使用“|”运行这个多命令 shell在蟒蛇

Question

我有这个 shell 命令，我想在 python 中得到它的字符串输出。

ip link show | egrep -o '([-_.[:alnum:]]+-eth[[:digit:]]+)'

会输出：

s1-eth1
s3-eth1
s4-eth2
...

使用os.system 返回整数错误值。

我试过了：

from subprocess import Popen, PIPE
import shlex

cmd1 = shlex.split('ip link show')
cmd2 = shlex.split("egrep -o '([-_.[:alnum:]]+-eth[[:digit:]]+)'")
proc1 = Popen(cmd1,stdout=PIPE)
proc2 = Popen(cmd2,stdin=proc1.stdout,stdout=PIPE,stderr=PIPE)
proc1.stdout.close()
out,err=proc2.communicate()
print('out: {0}'.format(out))
print('err: {0}'.format(err))

输出grep使用帮助

ip link show 会输出：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/ether 00:0c:29:b3:aa:25 brd ff:ff:ff:ff:ff:ff
3: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default 
    link/ether d2:c1:69:6f:ba:0d brd ff:ff:ff:ff:ff:ff
912: s2-eth3@s1-eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb master ovs-system state UP mode DEFAULT group default qlen 1000
    link/ether de:3e:e2:5a:56:b3 brd ff:ff:ff:ff:ff:ff
913: s1-eth1@s2-eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb master ovs-system state UP mode DEFAULT group default qlen 1000
    link/ether 1e:67:0b:14:7d:c9 brd ff:ff:ff:ff:ff:ff
914: s3-eth3@s1-eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb master ovs-system state UP mode DEFAULT group default qlen 1000
    link/ether da:05:df:f2:02:66 brd ff:ff:ff:ff:ff:ff
915: s1-eth2@s3-eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc htb master ovs-system state UP mode DEFAULT group default qlen 1000
    link/ether de:cc:94:85:81:22 brd ff:ff:ff:ff:ff:ff
...

我想从中获取这些值： s2-eth3 s1-eth1 ...

Answer 1

使用 'subprocess' 模块中的 'check_output' 函数：

from subprocess import check_output

out = check_output(["ip link show | egrep -o '([-_.[:alnum:]]+-eth[[:digit:]]+)'"])
out2 = str(out, encoding='utf-8')

print(out2)

祝你好运。