SeaRiver Blog

           介绍一下gensub()的用法：
           gensub(regexp, replacement, how [, target])    //返回值是要得到的字串
 
           例如1:
           awk 'BEGIN{print gensub( /foo/, "bar", 2 , "foo bar foobar")}'
           和
           echo "foo bar foobar"|sed -e 's/foo/bar/2'     //2可以是g,等同与SED里的g,全局
           以及
           echo "foo bar foobar"|awk '{$0=gensub( /foo/, "bar", 2);print}'
 
           结果是一样的
 
           例如2:
           [root@jp-test-apache qmHandle]# echo abc abc def|awk '{print gensub(/abc/,"ABC",1)}'
           ABC abc def
           [root@jp-test-apache qmHandle]# echo abc abc def|awk '{print gensub(/abc/,"ABC",2)}'
           abc ABC def
           [root@jp-test-apache qmHandle]# echo abc abc abc def|awk '{print gensub("abc","ABC",3)}'
           abc abc ABC def

           实例:
           [root@jp-test-apache qmHandle]# pgrep http| awk '{print "kill -9 " gensub(//,"",$1)}'
           kill -9 18855
           kill -9 18856
           kill -9 18857
           kill -9 18858
           kill -9 18859
           kill -9 18860