Golang os.Chmod() function is “used to change the mode of a file”. If the file is a symbolic link, it changes the mode of the link’s target. If there is an error, it will be of type *PathError.
Syntax
func Chmod(name string, mode FileMode) errorParameters
- name (string): The name of the file (or directory) whose mode you want to change.
- mode (os.FileMode): The new mode for the file. This is a bitmask that specifies the file’s permissions.
Return value
The return type of the os.Chmod() function is an error; it returns <nil> if there is no error; otherwise, it returns an error.
Example 1: How to Use os.Chmod() Function
Here’s an example that changes the permissions of a file to be readable, writable, and executable by the owner, and just readable by everyone else.
package main
import (
"fmt"
"os"
)
func main() {
filename := "new.txt"
err := os.Chmod(filename, 0744)
if err != nil {
fmt.Println("Error changing file mode:", err)
return
}
fmt.Printf("Changed permissions for %s successfully.\n", filename)
}Output
Changed permissions for new.txt successfully.Example 2: Change Permissions of Multiple Files
This code will change the permissions of multiple files to read-only for everyone.
package main
import (
"fmt"
"os"
)
func main() {
files := [3]string{"data.txt",
"npfile.txt",
"runes.txt"}
for _, file := range files {
err := os.Chmod(file, 0444)
if err != nil {
fmt.Printf("Error changing permissions for %s: %s\n", file, err)
continue
}
fmt.Printf("Changed permissions for %s to read-only.\n", file)
}
}Output
Changed permissions for data.txt to read-only.
Changed permissions for npfile.txt to read-only.
Changed permissions for runes.txt to read-only.Example 3: Toggle Execute Permission for Owner
package main
import (
"fmt"
"os"
)
func main() {
filename := "script.sh"
// Get the current permissions of the file
fileInfo, err := os.Stat(filename)
if err != nil {
fmt.Println("Error retrieving file info:", err)
return
}
currentMode := fileInfo.Mode()
ownerExecutePermission := os.FileMode(0100)
if currentMode&ownerExecutePermission != 0 {
err = os.Chmod(filename, currentMode-ownerExecutePermission)
if err == nil {
fmt.Printf("%s is now not executable by the owner.\n", filename)
}
} else {
err = os.Chmod(filename, currentMode|ownerExecutePermission)
if err == nil {
fmt.Printf("%s is now executable by the owner.\n", filename)
}
}
if err != nil {
fmt.Println("Error changing file mode:", err)
}
}
Output
Error retrieving file info: stat script.sh: no such file or directoryI got the error because of the script.sh. The file does not exist.
That’s it!
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Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.