// redir compiles a Redir into a op.
func (cp *compiler) redir(n *parse.Redir) op {
var dstOp valuesOp
if n.Dest != nil {
dstOp = cp.compound(n.Dest)
}
p := n.Begin()
srcOp := cp.compound(n.Source)
sourceIsFd := n.SourceIsFd
pSrc := n.Source.Begin()
mode := n.Mode
flag := makeFlag(mode)
return func(ec *evalCtx) {
var dst int
if dstOp == nil {
// use default dst fd
switch mode {
case parse.Read:
dst = 0
case parse.Write, parse.ReadWrite, parse.Append:
dst = 1
default:
// XXX should report parser bug
panic("bad RedirMode; parser bug")
}
} else {
// dst must be a valid fd
dst = ec.must(dstOp(ec), "FD", p).mustOneNonNegativeInt()
}
ec.growPorts(dst + 1)
ec.ports[dst].close()
srcMust := ec.must(srcOp(ec), "redirection source", pSrc)
src := string(srcMust.mustOneStr())
if sourceIsFd {
if src == "-" {
// close
ec.ports[dst] = &port{}
} else {
fd := srcMust.zerothMustNonNegativeInt()
ec.ports[dst] = ec.ports[fd]
if ec.ports[dst] != nil {
ec.ports[dst].closeF = false
ec.ports[dst].closeCh = false
}
}
} else {
f, err := os.OpenFile(src, flag, defaultFileRedirPerm)
if err != nil {
ec.errorf(p, "failed to open file %q: %s", src, err)
}
ec.ports[dst] = &port{
f: f, ch: make(chan Value), closeF: true, closeCh: true,
}
}
}
}
func (cp *compiler) redirOp(n *parse.Redir) Op {
return Op{cp.redir(n), n.Begin(), n.End()}
}