func CdCmd(scp *variables.Scope, ioc *T.IOContainer, args []string) T.ExitStatus {
// This does not conform to the posix spec.
// Very simplified. Cd to first arg or attempt to cd to home dir
cdTarget := "."
if len(args) == 0 {
homeDir := scp.Get("HOME")
if homeDir.Val == "" {
// Implementation defined behaviour. We try to grab
// the homedir of the current user
u, err := user.Current()
if err == nil {
cdTarget = u.HomeDir
}
} else {
cdTarget = homeDir.Val
}
} else {
cdTarget = args[0]
}
if err := scp.SetPwd(cdTarget); err != nil {
fmt.Fprintf(os.Stderr, "%s\n", err.Error())
return T.ExitFailure
}
return T.ExitSuccess
}
func (s SubVariable) Sub(scp *variables.Scope) (returnString string) {
logex.Debug("Substituting variable")
defer func() {
logex.Debugf("Returned '%s'", returnString)
}()
v := scp.Get(s.VarName)
switch s.SubType {
case VarSubNormal:
return v.Val
case VarSubLength:
// For the values ${#*} and ${#@}
// the number of positional parameters is returned
// We need to perform IFS splitting to figure this out
return strconv.Itoa(len(v.Val))
}
varExists := v.Set == true
// CheckNull means that an empty string is treated as unset
if s.CheckNull {
varExists = varExists && v.Val != ""
}
switch s.SubType {
case VarSubAssign:
if varExists {
return v.Val
}
scp.Set(s.VarName, s.SubVal)
return s.SubVal
case VarSubMinus:
if varExists {
return v.Val
}
return s.SubVal
case VarSubPlus:
if varExists {
return ""
}
return s.SubVal
case VarSubQuestion:
if varExists {
return v.Val
}
if s.SubVal != "" {
ExitShellWithMessage(T.ExitFailure, s.SubVal)
}
ExitShellWithMessage(T.ExitFailure, s.VarName+": Parameter not set")
case VarSubTrimRight, VarSubTrimRightMax, VarSubTrimLeft, VarSubTrimLeftMax:
ExitShellWithMessage(T.ExitFailure, "Trim operations not implemented")
}
logex.Fatal("SubVariable.Sub unreached")
return ""
}
func (n NodeFor) Eval(scp *variables.Scope, ioc *T.IOContainer) T.ExitStatus {
returnExit := T.ExitSuccess
expandedArgs := make([]string, len(n.Args))
for i, arg := range n.Args {
// This will need to be changed when IFS splitting is coded.
// Append each split as a seperate item
expandedArgs[i] = arg.Expand(scp)
}
for _, arg := range expandedArgs {
scp.Set(n.LoopVar, arg)
returnExit = n.Body.Eval(scp, ioc)
}
return returnExit
}
func (s SubSubshell) Sub(scp *variables.Scope) (returnString string) {
logex.Debug("Substituting shell")
defer func() {
logex.Debugf("Returned '%s'", returnString)
}()
if _, isNoop := s.N.(NodeNoop); isNoop {
return ""
}
out := &bytes.Buffer{}
// Not sure if we need to capture this exit code for the $? var.
// Ignore it for now
_ = s.N.Eval(scp.Copy(), &T.IOContainer{&bytes.Buffer{}, out, os.Stderr})
return strings.TrimRight(out.String(), "\n")
}
func (n NodePipe) Eval(scp *variables.Scope, ioc *T.IOContainer) T.ExitStatus {
lastPipeReader, pipeWriter := io.Pipe()
scp = scp.Copy()
cmd := n.Commands[0]
go cmd.Eval(scp, &T.IOContainer{In: &bytes.Buffer{}, Out: pipeWriter, Err: ioc.Err})
for _, cmd = range n.Commands[1 : len(n.Commands)-1] {
pipeReader, pipeWriter := io.Pipe()
go cmd.Eval(scp, &T.IOContainer{In: lastPipeReader, Out: pipeWriter, Err: ioc.Err})
lastPipeReader = pipeReader
}
cmd = n.Commands[len(n.Commands)-1]
if !n.Background {
return cmd.Eval(scp, &T.IOContainer{In: lastPipeReader, Out: ioc.Out, Err: ioc.Err})
}
go cmd.Eval(scp, &T.IOContainer{In: lastPipeReader, Out: ioc.Out, Err: ioc.Err})
return T.ExitSuccess
}
func (n NodeCommand) execExternal(scp *variables.Scope, ioc *T.IOContainer, args []string) T.ExitStatus {
// This is needed so that pipes will terminate
if pw, isPipeWriter := ioc.Out.(*io.PipeWriter); isPipeWriter {
defer func() {
if err := pw.Close(); err != nil {
panic(err) // XXX: Print error to stdout and continue?
}
}()
}
cmd := exec.Command(args[0], args[1:]...)
cmd.Env = scp.Environ()
cmd.Stdin = ioc.In
cmd.Stderr = ioc.Err
cmd.Stdout = ioc.Out
err := cmd.Run()
if err == nil {
return T.ExitSuccess
}
return T.ExitFailure
}
func (n NodeCommand) Eval(scp *variables.Scope, ioc *T.IOContainer) T.ExitStatus {
// A line with only assignments applies them to the Root Scope
// We check this first to avoid unnecessary scope Push/Pop's
if len(n.Args) == 0 {
for k, v := range n.Assign {
scp.Set(k, v.Expand(scp))
}
return T.ExitSuccess
}
// Minimum of len(n.Args) after expansions, Likely
// that it will be more after globbing though
expandedArgs := []string{}
for _, arg := range n.Args {
expandedArgs = append(expandedArgs, arg.Expand(scp))
}
// Order of precedence:
// Relative command > Builtin > User Function > Other external command
command := expandedArgs[0]
builtinFunc, builtinFound := builtins.All[command]
userFunc, userFuncFound := scp.Functions[command]
if strings.ContainsRune(command, '/') || (!builtinFound && !userFuncFound) {
scp.Push()
defer scp.Pop()
for k, v := range n.Assign {
scp.Set(k, v.Expand(scp), variables.LocalScope)
}
return n.execExternal(scp, ioc, expandedArgs)
}
if builtinFound {
return builtinFunc(scp, ioc, expandedArgs[1:])
}
if userFuncFound {
x := userFunc.(NodeFunction)
return x.EvalFunc(scp, ioc, expandedArgs[1:])
}
return T.ExitUnknownCommand
}
func LocalCmd(scp *variables.Scope, ioc *T.IOContainer, args []string) T.ExitStatus {
// Local should also do assignments, split args on equal sign? already
// expanded
for _, a := range args {
tmp := scp.Get(a)
if tmp.Set {
scp.Set(a, tmp.Val, variables.LocalScope)
} else {
scp.Set(a, "", variables.LocalScope)
}
}
return T.ExitSuccess
}
func (n NodeFunction) EvalFunc(scp *variables.Scope, ioc *T.IOContainer, args []string) T.ExitStatus {
scp.PushFunction(args)
defer scp.Pop()
return n.Body.Eval(scp, ioc)
}