linux bash多行取值

Question

#! /bin/bash
# process-monitor.sh

process=$1
pid=$(ps x | grep "hadoop" | grep '/bin/java' | grep -v grep | awk '{print $1}')
echo $pid`

上面是脚本，执行后返回值有多个pid：

10725 10855 11034 11289 11425

比如我想取第一个10725，该怎么写，感谢🙏。

Answer 1

pid=$(ps x | grep "hadoop" | grep '/bin/java' | grep -m1 -v grep | awk '{print $1}')

还有一种更优雅的解决方案可以避免grep -v grep这种方式:

pid=$(ps x | grep '[h]adoop' | grep -m1 '/bin/java' | awk '{print $1}')

See: https://unix.stackexchange.co...

Answer 2

cut -d ' ' -f 1
解释：以空格为分隔符，取第一列