go-mtree/vis.go

27 lines
700 B
Go

package mtree
// #include "vis.h"
// #include <stdlib.h>
import "C"
import (
"fmt"
"math"
"unsafe"
)
// Vis is a wrapper of the C implementation of the function vis, which encodes
// a character with a particular format/style
func Vis(src string) (string, error) {
// dst needs to be 4 times the length of str, must check appropriate size
if uint32(len(src)*4+1) >= math.MaxUint32/4 {
return "", fmt.Errorf("failed to encode: %q", src)
}
dst := string(make([]byte, 4*len(src)+1))
cDst, cSrc := C.CString(dst), C.CString(src)
defer C.free(unsafe.Pointer(cDst))
defer C.free(unsafe.Pointer(cSrc))
C.strvis(cDst, cSrc, C.VIS_WHITE|C.VIS_OCTAL|C.VIS_GLOB)
return C.GoString(cDst), nil
}