| 103 | } |
| 104 | |
| 105 | func (r *RotatingFile) rotate() error { |
| 106 | if err := r.file.Close(); err != nil { |
| 107 | return err |
| 108 | } |
| 109 | |
| 110 | // Remove the oldest backup if it exists |
| 111 | oldest := fmt.Sprintf("%s.%d", r.path, r.maxBackups) |
| 112 | _ = os.Remove(oldest) |
| 113 | |
| 114 | // Shift existing backups: .2 -> .3, .1 -> .2, etc. |
| 115 | for i := r.maxBackups - 1; i >= 1; i-- { |
| 116 | oldPath := fmt.Sprintf("%s.%d", r.path, i) |
| 117 | newPath := fmt.Sprintf("%s.%d", r.path, i+1) |
| 118 | _ = os.Rename(oldPath, newPath) |
| 119 | } |
| 120 | |
| 121 | // Rename current log to .1 |
| 122 | if err := os.Rename(r.path, r.path+".1"); err != nil && !os.IsNotExist(err) { |
| 123 | return err |
| 124 | } |
| 125 | |
| 126 | r.size = 0 |
| 127 | return r.openFile() |
| 128 | } |