Solution: read several files



examples/read-several-files/read_several_files.go
package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "strconv"
    "strings"
)

func div(a, b int) (res int, err error) {
    defer func() {
        myerr := recover()
        if myerr != nil {
            // fmt.Printf("%T %v\n", myerr, myerr)
            err = fmt.Errorf("bad")
        }
    }()

    res = a / b
    return
}

func main() {
    files := os.Args[1:]
    if len(files) == 0 {
        fmt.Println("We need at least one file")
        os.Exit(1)
    }
    for _, filename := range files {
        dat, err := ioutil.ReadFile(filename)
        if err != nil {
            fmt.Printf("Could not open file '%v' because: %v\n", filename, err)
            continue
        }

        text := strings.TrimSuffix(string(dat), "\n")
        parts := strings.Split(text, ",")
        a, err := strconv.Atoi(parts[0])
        if err != nil {
            fmt.Printf("Could not convert '%v' to integer: %v", parts[0], err)
            continue
        }
        b, err := strconv.Atoi(parts[1])
        if err != nil {
            fmt.Printf("Could not convert '%v' to integer: %v", parts[1], err)
            continue
        }

        c, err := div(a, b)
        if err != nil {
            fmt.Printf("Could not divide %v / %v Error: %v", a, b, err)
        }
        fmt.Println(c)
    }
}

examples/read-several-files/read_several_files.out
2
Could not open file 'b.txt' because: open b.txt: no such file or directory
Could not divide 4 / 0 Error: bad0
7