nix-amer/internal/instruction/copy.go

83 lines
1.8 KiB
Go

package instruction
import (
"fmt"
"os"
"strings"
)
type copy struct {
raw string
Src string
Dst string
}
func (d *copy) Raw() string { return strings.Join([]string{"copy", d.raw}, " ") }
func (d *copy) Build(_args string) error {
// 1. extract action (sub command)
split := strings.Split(_args, " ")
// 2. check syntax
if len(split) != 2 {
return ErrInvalidSyntax
}
d.Src = strings.Trim(split[0], " \t")
d.Dst = strings.Trim(split[1], " \t")
d.raw = _args
return nil
}
func (d copy) Exec(ctx ExecutionContext) ([]byte, error) {
// 1. fail if source file not found
if _, err := os.Stat(d.Src); os.IsNotExist(err) {
return nil, fmt.Errorf("cannot find script '%s'", d.Src)
}
// 2. execute script
if err := ctx.Executor.Command("cp", d.Src, d.Dst).Run(); err != nil {
return nil, fmt.Errorf("cannot copy '%s' to '%s' | %s", d.Src, d.Dst, err)
}
return nil, nil
}
func (d copy) DryRun(ctx ExecutionContext) ([]byte, error) {
// 1. fail if source file not found
if _, err := os.Stat(d.Src); os.IsNotExist(err) {
return nil, fmt.Errorf("cannot find file '%s'", d.Src)
}
// 2. if destination to create : try to create (then remove)
if _, err := os.Stat(d.Src); os.IsNotExist(err) {
file, err := os.OpenFile(d.Dst, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return nil, fmt.Errorf("cannot copy '%s' to '%s' | %s", d.Src, d.Dst, err)
}
file.Close()
if err := os.Remove(d.Dst); err != nil {
return nil, fmt.Errorf("cannot tmp file at '%s' | %s", d.Dst, err)
}
return nil, nil
}
// 3. if destination exists : check write permission
file, err := os.OpenFile(d.Dst, os.O_APPEND|os.O_WRONLY, 0600)
if err != nil {
return nil, fmt.Errorf("cannot copy '%s' to '%s' | %s", d.Src, d.Dst, err)
}
file.Close()
return nil, nil
}