Golang使用bufio.Scanner多次扫描同一行

Question

I am writing a code which scans a test file and replaces the text with something else. Would like to replace same set of lines with different texts stacked one below the other. One option i found is using the tee function of ioreader, but is there a better way to achieve the same.

For instance, what i am trying to achieve is replacing the methodtype substring in below piece of text with different strings like GET, POST, etc. To get the output as below:

TEXT:

router.Methods("methodtype").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse,
append(options, kitHttp.ServerBefore())...

OUTPUT:

router.Methods("GET").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse,
append(options, kitHttp.ServerBefore())...


router.Methods("PUT").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse,
append(options, kitHttp.ServerBefore())...

router.Methods("POST").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse,
append(options, kitHttp.ServerBefore())...

Answer 1

In order to replace text, you can use text/template instead of bufio:

Playground: https://play.golang.org/p/7HYBqxtJ3KB

package main

import (
    "fmt"
    "text/template"
    "os"
)

type method struct {
    MethodType string
}

func main() {

    buf := `router.Methods("{{.MethodType}}").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse, append(options, kitHttp.ServerBefore())...
`

    tmpl, err := template.New("test").Parse(buf)
    if err != nil {
        panic(err)
    }

    methods := []string{"GET", "PUT", "POST"}

    for _, m := range methods {
        err = tmpl.Execute(os.Stdout, method{MethodType: m})
        if err != nil {
            fmt.Println(err.Error())
        }
    }

}

Output:

router.Methods("GET").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse, append(options, kitHttp.ServerBefore())...
router.Methods("PUT").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse, append(options, kitHttp.ServerBefore())...
router.Methods("POST").Path(templatepackagespec.MethodtypePath).Handler(kitHttp.NewServer(endpoints.FuncnameEndpoint
httptransport.EncodeResponse, append(options, kitHttp.ServerBefore())...