效果

源码

package main

import (
	"fmt"
	"regexp"
	"strings"

	"gitee.com/liumou_site/gbm"
)

func Grep(txt, sub string) []string {
	var res string

	re := "(.*)" + sub + "[^s]*"

	c, err := regexp.Compile(re)
	if err != nil {
		panic(err)
	}
	TxtSp := strings.Split(txt, "\n")
	for _, v := range TxtSp {
		tmp := c.FindAllString(v, -1)
		if len(tmp) > 0 {
			res = res + tmp[0] + "\n"
		}
	}
	r := strings.Split(res, "\n")
	return gbm.SliceRemoveNull(r)
}
func main() {
	txt := `Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
	default         JDBoxV3.lan     0.0.0.0         UG    600    0        0 wlo1
	10.1.1.0        0.0.0.0         255.255.255.0   U     600    0        0 wlo1
	172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
	172.18.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-bb1893ff49af
	172.19.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-823a20cdeae2
	192.168.100.0   0.0.0.0         255.255.255.0   U     0      0        0 virbr1
	`
	r := Grep(txt, "172")
	for i, v := range r {
		fmt.Println(i, v)
	}
}