[spec/command_] Only search for executable files.

Command execution, command -v, and type -t now only search for
executable files.

'source' searches for non-executables, and is not cached.

Also re-organize spec tests.

core/process.py

@@ -469,8 +469,9 @@ def _Exec(self, argv0_path, argv, argv0_spid, environ, should_retry):
     except OSError as e:
       # Run with /bin/sh when ENOEXEC error (no shebang).  All shells do this.
       if e.errno == errno.ENOEXEC and should_retry:
-        self._Exec('/bin/sh', ['/bin/sh', argv0_path] + argv[1:], argv0_spid,
-                   environ, False)
+        new_argv = ['/bin/sh', argv0_path]
+        new_argv.extend(argv[1:])
+        self._Exec('/bin/sh', new_argv, argv0_spid, environ, False)
         # NO RETURN
 
       # Would be nice: when the path is relative and ENOENT: print PWD and do

demo/path-cache.sh

@@ -13,7 +13,7 @@ set -o errexit
 
 sh-demo() {
   local sh=$1
-  local syscalls='execve,stat,lstat'
+  local syscalls='execve,stat,lstat,access'
   #local syscalls='execve'
   strace -ff -e $syscalls  -- $sh -c 'whoami; whoami'
 }

osh/cmd_exec.py

@@ -219,7 +219,7 @@ def _Source(self, arg_vec):
     except IndexError:
       raise args.UsageError('missing required argument')
 
-    resolved = self.search_path.Lookup(path)
+    resolved = self.search_path.Lookup(path, exec_required=False)
     if resolved is None:
       resolved = path
     try:

osh/state.py

@@ -46,7 +46,7 @@ def __init__(self, mem):
     self.mem = mem
     self.cache = {}
 
-  def Lookup(self, name):
+  def Lookup(self, name, exec_required=True):
     """
     Returns the path itself (for relative path), the resolve path, or None.
     """
@@ -66,7 +66,16 @@ def Lookup(self, name):
 
     for path_dir in path_list:
       full_path = os_path.join(path_dir, name)
-      if path_stat.exists(full_path):
+
+      # NOTE: dash and bash only check for EXISTENCE in 'command -v' (and 'type
+      # -t').  OSH follows mksh and zsh.  Note that we can still get EPERM if
+      # the permissions are changed between check and use.
+      if exec_required:
+        found = posix.access(full_path, posix.X_OK)
+      else:
+        found = path_stat.exists(full_path)  # for 'source'
+
+      if found:
         return full_path
 
     return None

spec/builtin-bash.test.sh

@@ -44,18 +44,16 @@ file
 file
 ## END
 
-#### type -t and command -v with non-executable file still finds it
-
-# PATH resolution is different
-
+#### type -t doesn't find non-executable (like command -v)
 PATH="$TMP:$PATH"
 touch $TMP/non-executable
 type -t non-executable
-command -v not-executable | grep -o /not-executable
-## STDOUT:
+## stdout-json: ""
+## status: 1
+## BUG bash STDOUT:
 file
-/not-executable
 ## END
+## BUG bash status: 0
 
 #### type -t -> not found
 type -t echo ZZZ find =

spec/builtin-eval-source.test.sh

@@ -155,6 +155,16 @@ status=127
 ## N-I mksh stdout-json: ""
 ## N-I mksh status: 1
 
+#### source looks in PATH for files
+mkdir -p dir
+echo "echo hi" > dir/cmd
+PATH="dir:$PATH"
+. cmd
+rm dir/cmd
+## STDOUT:
+hi
+## END
+
 #### source finds files in PATH before current dir
 cd $TMP
 mkdir -p dir
@@ -167,6 +177,15 @@ echo status=$?
 path
 status=0
 ## END
+
+#### source works for files in subdirectory
+mkdir -p dir
+echo "echo path" > dir/cmd
+. dir/cmd
+rm dir/cmd
+## STDOUT:
+path
+## END
 
 #### exit within eval (regression)
 eval 'exit 42'

spec/builtins2.test.sh

@@ -57,6 +57,32 @@ myfunc
 status=1
 ## END
 
+#### command -v doesn't find non-executable file
+# PATH resolution is different
+
+PATH="$TMP:$PATH"
+touch $TMP/non-executable $TMP/executable
+chmod +x $TMP/executable
+
+command -v non-executable | grep -o /non-executable
+echo status=$?
+
+command -v executable | grep -o /executable
+echo status=$?
+
+## STDOUT:
+status=1
+/executable
+status=0
+## END
+
+## BUG bash/dash STDOUT:
+/non-executable
+status=0
+/executable
+status=0
+## END
+
 #### command skips function lookup
 seq() {
   echo "$@"

spec/command_.test.sh

@@ -187,9 +187,9 @@ status=0
 status=0
 ## END
 
-#### hash -r with additional args
-hash -r extra >/dev/null  # avoid weird output with mksh
+#### hash -r doesn't allow additional args
+hash -r whoami >/dev/null  # avoid weird output with mksh
 echo status=$?
 ## stdout: status=1
 ## OK osh stdout: status=2
-## BUG dash stdout: status=0
+## BUG dash/bash stdout: status=0

spec/posix.test.sh

@@ -140,22 +140,8 @@ one
 EOF1
 three
 EOF2
-## stdout-json: "one\ntwo\nthree\n"
-
-#### source works for files in subdirectory
-mkdir -p dir
-echo "echo path" > dir/cmd
-. dir/cmd
-rm dir/cmd
-## STDOUT:
-path
-
-#### source looks in PATH for files
-mkdir -p dir
-echo "echo hi" > dir/cmd
-PATH="dir:$PATH"
-. cmd
-rm dir/cmd
 ## STDOUT:
-hi
+one
+two
+three
 ## END