This page (revision-3) was last changed on 29-Dec-2021 08:21 by Markus Monderkamp 

This page was created on 28-Dec-2021 22:07 by Markus Monderkamp

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Version Date Modified Size Author Changes ... Change note
3 29-Dec-2021 08:21 2 KB Markus Monderkamp to previous testfile.go
2 28-Dec-2021 22:07 1 KB Markus Monderkamp to previous | to last Datum ergänzt
1 28-Dec-2021 22:07 1 KB Markus Monderkamp to last Beispiele-Start mit Dateilesen, Modifizieren und Schreiben

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GoLangBeispiele
GoLangBeispiele

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!Beispiele in GoLang

Interpretieren: go run <file>
Kompilieren: go build <file>

----

!!read file, modify it and write it back (28.12.2021)

%%prettify
{{{
package main

// filemodify.go - read file, modify it and write it back

/*cat testdata/hello
hello gopher
hello helmut
*/

// inspired by:
// https://pkg.go.dev/io/ioutil#example-ReadFile on 20211228
// and
// https://www.geeksforgeeks.org/strings-replace-function-in-golang-with-examples/

import (
       "fmt"
       "io/ioutil"
       "log"
       "strings"
)

func main() {
       content, err := ioutil.ReadFile("testdata/hello")
       if err != nil {  
               log.Fatal(err)
       }

       //https://yourbasic.org/golang/convert-string-to-byte-slice/
       //s := string([]byte{65, 66, 67, 226, 130, 172})
       contentstring := string(content)

       //strings.Replace(contentstring, "helmut", "hannelore", -1) // -1 replaces all
       contentmodifiedstring := strings.Replace(contentstring, "h", "g", 2)
       //strings.ReplaceAll(contentstring, "h", "g")

       fmt.Printf("File contents:\n%s", contentmodifiedstring)

       //b := []byte("ABC€")
       contentbyte := []byte(contentmodifiedstring)

       //func WriteFile(filename string, data []byte, perm fs.FileMode) error
       errwrite := ioutil.WriteFile("testdata/hellomodified", contentbyte, 0644)
       if err != nil {
               log.Fatal(errwrite)
       }

}

}}}
/%

----


Fin
This page (revision-3) was last changed on 29-Dec-2021 08:21 by Markus Monderkamp  Top