With ioutil, we can read in the contents of a file (with ReadAll). Then we can write the copy to a new location. This logic can be placed in a reusable func.
Copy example. Here we have a main func that begins with 2 local variables. We must specify a valid input path (the source) and output path (the target).
Part 1 We open an input file with the os.Open func. We just ignore errors, but these could be checked.
Part 2 We read in the data from the file with ioutil.ReadAll. Again we just ignore errors.
Part 3 We call ioutil.WriteFile to write the data to a new location—the target location for the copy.
package main
import (
"fmt""io/ioutil""os"
)
func main() {
inputPath := `C:\programs\file.txt`
outputPath := `C:\programs\copy.txt`
// Part 1: open input file.
inputFile, _ := os.Open(inputPath)
// Part 2: call ReadAll to get contents of input file.
data, _ := ioutil.ReadAll(inputFile)
// Part 3: write data to copy file.
ioutil.WriteFile(outputPath, data, 0)
fmt.Println("DONE")
}DONE
Notes, copying. When we want to copy a file, we cannot just call os.Rename as the original is deleted. Instead, we can use helpful methods from ioutil.
file.txt: 60 bytes
copy.txt: 60 bytes
Summary. Often it is important to copy files for deployment of projects (like websites or applications). With the code here, we can copy files without deleting the originals.
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This page was last updated on Jan 27, 2025 (edit).