/
imgcat.go
70 lines (58 loc) · 1.37 KB
/
imgcat.go
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package imgcat
import (
"encoding/base64"
"io"
"strings"
"github.com/pkg/errors"
)
// Copy copies the given image reader and encodes it as an
// iTerm2 image into the writer.
func copy(w io.Writer, header, r, footer io.Reader) error {
pr, pw := io.Pipe()
go func() {
defer pw.Close()
wc := base64.NewEncoder(base64.StdEncoding, pw)
_, err := io.Copy(wc, r)
if err != nil {
pw.CloseWithError(errors.Wrap(err, "could not encode image"))
return
}
if err := wc.Close(); err != nil {
pw.CloseWithError(errors.Wrap(err, "could not close base64 encoder"))
return
}
}()
_, err := io.Copy(w, io.MultiReader(header, pr, footer))
return err
}
// NewWriter returns a new imgcat writer.
func NewWriter(w io.Writer, iterm2compatible bool) io.WriteCloser {
header := strings.NewReader("")
footer := strings.NewReader("")
if iterm2compatible {
header = strings.NewReader("\033]1337;File=inline=1:")
footer = strings.NewReader("\a\n")
}
pr, pw := io.Pipe()
wc := &writer{pw, make(chan struct{})}
go func() {
defer close(wc.done)
err := copy(w, header, pr, footer)
pr.CloseWithError(err)
}()
return wc
}
type writer struct {
pw *io.PipeWriter
done chan struct{}
}
func (w *writer) Write(data []byte) (int, error) {
return w.pw.Write(data)
}
func (w *writer) Close() error {
if err := w.pw.Close(); err != nil {
return err
}
<-w.done
return nil
}