Added golang examples with package, exec, envs, flags

examples/golang/cource/06a_exec/exec/exec.go

@@ -0,0 +1,33 @@
+package exec
+
+import (
+	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+	"bytes"
+)
+
+func Run_simple(c string) string {
+	cmd, err := exec.Command(c).Output()
+//	err := cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+	return string(cmd)
+}
+
+func Run_some_std_inout(s string) string {
+	cmd := exec.Command("tr", "a-z", "A-Z")
+
+	cmd.Stdin = strings.NewReader(s)
+	var out bytes.Buffer
+	cmd.Stdout = &out
+
+	err := cmd.Run()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return fmt.Sprintf("Converted string: %q", out.String())
+}

examples/golang/cource/06a_exec/exec/pipe.go

@@ -0,0 +1,53 @@
+package exec
+
+import (
+	"fmt"
+	"log"
+	"os/exec"
+	"io"
+	"io/ioutil"
+)
+
+func Run_with_in_pipe(c string, data string) string {
+	cmd := exec.Command(c)
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	go func() {
+		defer stdin.Close()
+		io.WriteString(stdin, data)
+	}()
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return fmt.Sprintf("%s", out)
+}
+
+
+func Run_with_out_pipe(c string, arg ...string) string {
+	cmd := exec.Command(c, arg...)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if err := cmd.Start(); err != nil {
+		log.Fatal(err)
+	}
+
+	data, err := ioutil.ReadAll(stdout)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if err := cmd.Wait(); err != nil {
+		log.Fatal(err)
+	}
+
+	return fmt.Sprintf("%s", string(data))
+}

examples/golang/cource/06a_exec/go.mod

@@ -0,0 +1,3 @@
+module 06a_exec
+
+go 1.23.2

examples/golang/cource/06a_exec/main.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+	"golang/cource/06a_exec/exec"
+)
+
+func main() {
+	fmt.Println(exec.Run_simple("ls"))
+	fmt.Println(exec.Run_some_std_inout("Test string replace"))
+	fmt.Println(exec.Run_with_in_pipe("cat", "Some strange test string by pipe"))
+	fmt.Println(exec.Run_with_out_pipe("ping", "-c 1", "8.8.8.8"))
+}

examples/golang/cource/06b_envs.go

@@ -0,0 +1,18 @@
+// for more see to go-env library or other
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	os.Setenv("SOME_MY_ENV", "in_the_water")
+	fmt.Println("SOME_MY_ENV:", os.Getenv("SOME_MY_ENV"))
+	fmt.Println("SEUPER_PASS:", os.Getenv("SUPER_PASS"))
+	fmt.Println()
+
+	for _, e := range os.Environ() {
+		fmt.Println(e)
+	}
+}

examples/golang/cource/06c_flags.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+func main() {
+	nameFlag := flag.String("name", "Peter", "a string with animal name")
+	ageFlag := flag.Int("age", 34, "an int with age of animal")
+	aliveFlag := flag.Bool("alive", true, "a bool about aliveness")
+
+	var somevar string
+	flag.StringVar(&somevar, "somevar", "data", "a string var to var!")
+
+	flag.Parse()
+
+	fmt.Println("Name:", *nameFlag)
+	fmt.Println("Age:", *ageFlag)
+	fmt.Println("Is alive?", *aliveFlag)
+	fmt.Println("Somevar", somevar)
+	fmt.Println("Next args: ", flag.Args())
+}
+