1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
package out
import (
"os"
"path"
)
// LazyFile is an io.WriteCloser which defers creation of the file it is supposed to write in
// till the first call to its write function in order to prevent creation of file, if no write
// is supposed to happen.
type LazyFile struct {
// FileName is path to the file to which genny will write.
FileName string
file *os.File
}
// Close closes the file if it is created. Returns nil if no file is created.
func (lw *LazyFile) Close() error {
if lw.file != nil {
return lw.file.Close()
}
return nil
}
// Write writes to the specified file and creates the file first time it is called.
func (lw *LazyFile) Write(p []byte) (int, error) {
if lw.file == nil {
err := os.MkdirAll(path.Dir(lw.FileName), 0755)
if err != nil {
return 0, err
}
lw.file, err = os.Create(lw.FileName)
if err != nil {
return 0, err
}
}
return lw.file.Write(p)
}
|
