来自：
https://zhidao.baidu.com/question/369911229489608484.html
time=`cat json|awk -F"[xxx]" '/xxx/{print $x}'`
json.txt:
{
    "people": [
        {
            "firstName": "Brett",
            "lastName": "McLaughlin",
            "email": "aaaa"
        },
        {
            "firstName": "Jason",
            "lastName": "Hunter",
            "email": "bbbb"
        },
        {
            "firstName": "Elliotte",
            "lastName": "Harold",
            "email": "cccc"
        }
    ]
}
 cat json.txt | awk -F "[firstName]" '/firstName/{print$0}'
[root@localhost liu]# more json.txt | awk -F "[firstName]" '/firstName/{print$0}'
[root@localhost liu]# less json.txt | awk -F "[firstName]" '/firstName/{print$0}'
输出到一个文件
less json.txt | awk -F "[firstName]" '/firstName/{print$0}' > out.log
结果：
            "firstName": "Brett",
            "firstName": "Jason",
            "firstName": "Elliotte",


less out.log | awk -F "[:]" '/firstName/{print$2}'
结果：
 "Brett",
 "Jason",
 "Elliotte",