moby/cli/command/utils.go
John Howard c98e77c77c Windows: Use sequential file access
Signed-off-by: John Howard <jhoward@microsoft.com>
2017-01-23 10:25:36 -08:00

90 lines
2 KiB
Go

package command
import (
"fmt"
"io"
"os"
"path/filepath"
"runtime"
"strings"
"github.com/docker/docker/pkg/system"
)
// CopyToFile writes the content of the reader to the specified file
func CopyToFile(outfile string, r io.Reader) error {
// We use sequential file access here to avoid depleting the standby list
// on Windows. On Linux, this is a call directly to ioutil.TempFile
tmpFile, err := system.TempFileSequential(filepath.Dir(outfile), ".docker_temp_")
if err != nil {
return err
}
tmpPath := tmpFile.Name()
_, err = io.Copy(tmpFile, r)
tmpFile.Close()
if err != nil {
os.Remove(tmpPath)
return err
}
if err = os.Rename(tmpPath, outfile); err != nil {
os.Remove(tmpPath)
return err
}
return nil
}
// capitalizeFirst capitalizes the first character of string
func capitalizeFirst(s string) string {
switch l := len(s); l {
case 0:
return s
case 1:
return strings.ToLower(s)
default:
return strings.ToUpper(string(s[0])) + strings.ToLower(s[1:])
}
}
// PrettyPrint outputs arbitrary data for human formatted output by uppercasing the first letter.
func PrettyPrint(i interface{}) string {
switch t := i.(type) {
case nil:
return "None"
case string:
return capitalizeFirst(t)
default:
return capitalizeFirst(fmt.Sprintf("%s", t))
}
}
// PromptForConfirmation requests and checks confirmation from user.
// This will display the provided message followed by ' [y/N] '. If
// the user input 'y' or 'Y' it returns true other false. If no
// message is provided "Are you sure you want to proceed? [y/N] "
// will be used instead.
func PromptForConfirmation(ins *InStream, outs *OutStream, message string) bool {
if message == "" {
message = "Are you sure you want to proceed?"
}
message += " [y/N] "
fmt.Fprintf(outs, message)
// On Windows, force the use of the regular OS stdin stream.
if runtime.GOOS == "windows" {
ins = NewInStream(os.Stdin)
}
answer := ""
n, _ := fmt.Fscan(ins, &answer)
if n != 1 || (answer != "y" && answer != "Y") {
return false
}
return true
}