Implement 'command -v'.

Share logic with 'type -t', which largely does the same thing.

The other flags to 'command' aren't implemented yet.

Fixes issue #50.

core/builtin.py

@@ -61,7 +61,7 @@
TRUE FALSE
COLON
TEST BRACKET GETOPTS
TYPE HELP
COMMAND TYPE HELP
""".split())


@@ -203,6 +203,9 @@ def Resolve(argv0):
  elif argv0 == "getopts":
    return EBuiltin.GETOPTS

  elif argv0 == "command":
    return EBuiltin.COMMAND

  elif argv0 == "type":
    return EBuiltin.TYPE

@@ -668,45 +671,78 @@ def Unset(argv, mem, funcs):
  return 0


TYPE_SPEC = _Register('type')
TYPE_SPEC.ShortFlag('-t')

def Type(argv, funcs, path_val):
  arg, i = TYPE_SPEC.Parse(argv)

def _ResolveNames(names, funcs, path_val):
  if path_val.tag == value_e.Str:
    path_list = path_val.s.split(':')
  else:
    path_list = []  # treat as empty path

  status = 0
  if not arg.t:
    util.warn("*** 'type' builtin called without -t ***")
    status = 1
    # Keep going anyway

  for name in argv[i:]:
  results = []
  for name in names:
    if name in funcs:
      print('function')
      kind = ('function', name)
    elif Resolve(name) != EBuiltin.NONE:
      print('builtin')
      kind = ('builtin', name)
    elif ResolveSpecial(name) != EBuiltin.NONE:
      print('builtin')
      kind = ('builtin', name)
    elif lex.IsOtherBuiltin(name):  # declare, continue, etc.
      print('builtin')
      kind = ('builtin', name)
    elif lex.IsKeyword(name):
      print('keyword')
      kind = ('keyword', name)
    else:
      # Now look for files.
      found = False
      for path_dir in path_list:
        full_path = os.path.join(path_dir, name)
        if os.path.exists(full_path):
          print('file')
          kind = ('file', full_path)
          found = True
          break
      if not found:  # Nothing printed, but status is 1.
        status = 1
        kind = (None, None)
    results.append(kind)

  return results
    

COMMAND_SPEC = _Register('command')
COMMAND_SPEC.ShortFlag('-v')
COMMAND_SPEC.ShortFlag('-V')

def Command(argv, funcs, path_val):
  arg, i = COMMAND_SPEC.Parse(argv)
  status = 0
  if arg.v:
    for kind, arg in _ResolveNames(argv[i:], funcs, path_val):
      if kind is None:
        status = 1  # nothing printed, but we fail
      else:
        # This is for -v, -V is more detailed.
        print(arg)
  else:
    util.warn('*** command without -v not not implemented ***')
    status = 1

  return status


TYPE_SPEC = _Register('type')
TYPE_SPEC.ShortFlag('-t')

def Type(argv, funcs, path_val):
  arg, i = TYPE_SPEC.Parse(argv)

  status = 0
  if not arg.t:
    util.warn("*** 'type' builtin called without -t ***")
    status = 1
    # Keep going anyway

  for kind, arg in _ResolveNames(argv[i:], funcs, path_val):
    if kind is None:
      status = 1  # nothing printed, but we fail
    else:
      print(kind)

  return status

core/cmd_exec.py

@@ -303,6 +303,10 @@ def _RunBuiltin(self, builtin_id, argv):
    elif builtin_id == EBuiltin.GETOPTS:
      status = builtin.GetOpts(argv, self.mem)

    elif builtin_id == EBuiltin.COMMAND:
      path = self.mem.GetVar('PATH')
      status = builtin.Command(argv, self.funcs, path)

    elif builtin_id == EBuiltin.TYPE:
      path = self.mem.GetVar('PATH')
      status = builtin.Type(argv, self.funcs, path)
@@ -315,7 +319,7 @@ def _RunBuiltin(self, builtin_id, argv):
      status = builtin.DebugLine(argv, self.status_lines)

    else:
      raise AssertionError('Unhandled builtin: %d' % builtin_id)
      raise AssertionError('Unhandled builtin: %s' % builtin_id)

    assert isinstance(status, int)
    return status

spec/builtins2.test.sh

@@ -0,0 +1,26 @@
#!/bin/bash

### command -v
myfunc() { echo x; }
command -v echo
echo $?
command -v myfunc
echo $?
command -v nonexistent  # doesn't print anything?
echo $?
command -v for
echo $?
# stdout-json: "echo\n0\nmyfunc\n0\n1\nfor\n0\n"
# OK dash stdout-json: "echo\n0\nmyfunc\n0\n127\nfor\n0\n"

### command -v with multiple names
# bash chooses to swallow the error!  We agree with zsh if ANY word lookup
# fails, then the whole thing fails.
# All four shells behave differently here!
myfunc() { echo x; }
command -v echo myfunc ZZZ for
echo status=$?
# stdout-json: "echo\nmyfunc\nfor\nstatus=1\n"
# BUG bash stdout-json: "echo\nmyfunc\nfor\nstatus=0\n"
# BUG dash stdout-json: "echo\nstatus=0\n"
# OK mksh stdout-json: "echo\nmyfunc\nstatus=1\n"

test/spec.sh

@@ -256,6 +256,11 @@ builtins() {
    ${REF_SHELLS[@]} $OSH "$@"
}

builtins2() {
  sh-spec spec/builtins2.test.sh --osh-failures-allowed 0 \
    ${REF_SHELLS[@]} $ZSH $OSH "$@"
}

builtin-vars() {
  sh-spec spec/builtin-vars.test.sh --osh-failures-allowed 2 \
    ${REF_SHELLS[@]} $OSH "$@"