37 lines
764 B
Go
37 lines
764 B
Go
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// This program increments a given byte of a given file,
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// to test data corruption detection -- BE CAREFUL!
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package main
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import (
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"fmt"
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"os"
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"strconv"
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)
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func main() {
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if len(os.Args) != 3 {
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fmt.Println("usage:", os.Args[0], "file offset")
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os.Exit(1)
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}
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f, err := os.OpenFile(os.Args[1], os.O_RDWR, 0644)
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if err != nil {
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fmt.Println("open failed:", err)
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os.Exit(1)
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}
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offset, err := strconv.ParseInt(os.Args[2], 10, 64)
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if err != nil {
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fmt.Println("bad offset:", err)
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os.Exit(1)
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}
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b := make([]byte, 1)
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if n, err := f.ReadAt(b, offset); err != nil || n != 1 {
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fmt.Println("read failed:", n, err)
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os.Exit(1)
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}
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b[0] += 1
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if n, err := f.WriteAt(b, offset); err != nil || n != 1 {
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fmt.Println("read failed:", n, err)
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os.Exit(1)
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}
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}
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