// return file content as string, no errors
func httpfsRead(fname string) string {
data, err := httpfs.Read(fname)
if err != nil {
return ""
}
return string(data)
}
func CompileFile(fname string) (*script.BlockStmt, error) {
bytes, err := httpfs.Read(fname)
if err != nil {
return nil, err
}
return World.Compile(string(bytes))
}
func (g *guistate) servePlot(w http.ResponseWriter, r *http.Request) {
out := []byte{}
// handle error and return wheter err != nil.
handle := func(err error) bool {
if err != nil {
w.Write(emptyIMG())
g.Set("plotErr", err.Error()+string(out))
return true
} else {
return false
}
}
// limit max processes
atomic.AddInt32(&nPlots, 1)
defer atomic.AddInt32(&nPlots, -1)
if atomic.LoadInt32(&nPlots) > MAX_GNUPLOTS {
handle(errors.New("too many gnuplot processes"))
return
}
a := g.StringValue("usingx")
b := g.StringValue("usingy")
cmd := "gnuplot"
args := []string{"-e", fmt.Sprintf(`set format x "%%g"; set key off; set format y "%%g"; set term svg size 480,320 fsize 10; plot "-" u %v:%v w li; set output;exit;`, a, b)}
excmd := exec.Command(cmd, args...)
stdin, err := excmd.StdinPipe()
if handle(err) {
return
}
stdout, err := excmd.StdoutPipe()
if handle(err) {
return
}
data, err := httpfs.Read(fmt.Sprintf(`%vtable.txt`, OD()))
if handle(err) {
return
}
err = excmd.Start()
if handle(err) {
return
}
defer excmd.Wait()
_, err = stdin.Write(data)
if handle(err) {
return
}
err = stdin.Close()
if handle(err) {
return
}
out, err = ioutil.ReadAll(stdout)
if handle(err) {
return
}
w.Header().Set("Content-Type", "image/svg+xml")
w.Write(out)
g.Set("plotErr", "")
return
}