gilo/gilo.go
2021-03-19 16:02:05 -04:00

88 lines
1.4 KiB
Go

package main
import (
"bufio"
"fmt"
"golang.org/x/term"
"os"
)
func isAscii(char rune) bool {
ord := int(char)
return ord < 0x80
}
func isCtrl(char rune) bool {
if !isAscii(char) {
return false
}
ord := int(char)
return ord == 0x7f || ord < 0x20
}
// Return the input code of a Ctrl-key chord.
func ctrlKey(char rune) rune {
ord := int(char)
raw := ord & 0x1f
if !isCtrl(rune(raw)) {
return 0
}
return rune(raw)
}
// Put the terminal in raw mode
func rawOn() *term.State {
oldState, err := term.MakeRaw(int(os.Stdin.Fd()))
if err != nil {
panic(err)
}
return oldState
}
// Restore the terminal to canonical mode
func rawOff(oldState *term.State) {
err := term.Restore(int(os.Stdin.Fd()), oldState)
if err != nil {
panic(err)
}
}
// Print a formatted string to stdout, with CRLF line endings for proper terminal formatting
func outLn(format string, a ...interface{}) {
formatted := fmt.Sprintf(format, a...)
fmt.Printf("%s\r\n", formatted)
}
func main() {
// Go to proper raw mode, but restore canonical mode at extit
oldState := rawOn()
defer rawOff(oldState)
reader := bufio.NewReader(os.Stdin)
for {
char, _, err := reader.ReadRune()
if err != nil {
panic(err)
}
// Ugliest syntax structure ever?
switch {
case char == ctrlKey('q'):
outLn("bye!")
return
case isCtrl(char):
outLn("%d", char)
default:
outLn("%d ('%c')", char, char)
}
}
}