package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?ms)(xyz(?:(?!abc).)*?)123`)
var str = `abc----1
pqr----2
123----3
xyz----4
lll----5
pqr----6
123----7
qqq----8
xyz----5
abc----3
123----9`
var substitution = "$1456"
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/