msh: fix the case where the file has exec bit but can't be run directly

     (run "$SHELL $file" instead)
msh: fix exit codes when command is not found or can't be execed
     (with testcases)

5 files changed, 21 insertions, 6 deletions

diff --git a/shell/msh.c b/shell/msh.c
index 9e06a3bff..840c8bb93 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -594,7 +594,7 @@ static struct op *dowholefile(int /*, int*/);
 /* Globals */
 static char **dolv;
 static int dolc;
-static int exstat;
+static uint8_t exstat;
 static smallint gflg;                   /* (seems to be a parse error indicator) */
 static smallint interactive;            /* Is this an interactive shell */
 static smallint execflg;
@@ -806,7 +806,8 @@ static void warn(const char *s)
 {
         if (*s) {
                 prs(s);
-                exstat = -1;
+                if (!exstat)
+                        exstat = 255;
         }
         prs("\n");
         if (FLAG['e'])
@@ -3071,8 +3072,6 @@ static const char *rexecve(char *c, char **v, char **envp)
                 if (tp != global_env.linep)
                         *tp++ = '/';
                 strcpy(tp, c);
-                //for (i = 0; (*tp++ = c[i++]) != '\0';)
-                //      continue;
 
                 DBGPRINTF3(("REXECVE: global_env.linep is %s\n", global_env.linep));
 
@@ -3080,10 +3079,13 @@ static const char *rexecve(char *c, char **v, char **envp)
 
                 switch (errno) {
                 case ENOEXEC:
+                        /* File is executable but file format isnt recognized */
+                        /* Run it as a shell script */
+                        /* (execve above didnt do it itself, unlike execvp) */
                         *v = global_env.linep;
                         v--;
                         tp = *v;
-                        *v = global_env.linep;
+                        *v = (char*)DEFAULT_SHELL;
                         execve(DEFAULT_SHELL, v, envp);
                         *v = tp;
                         return "no shell";
@@ -3095,7 +3097,12 @@ static const char *rexecve(char *c, char **v, char **envp)
                         return "argument list too long";
                 }
         }
-        return errno == ENOENT ? "not found" : "cannot execute";
+        if (errno == ENOENT) {
+                exstat = 127; /* standards require this */
+                return "not found";
+        }
+        exstat = 126; /* mimic bash */
+        return "cannot execute";
 }
 
 /*
diff --git a/shell/msh_test/msh-execution/exitcode_EACCES.right b/shell/msh_test/msh-execution/exitcode_EACCES.right
new file mode 100644
index 000000000..b13682cde
--- /dev/null
+++ b/shell/msh_test/msh-execution/exitcode_EACCES.right
@@ -0,0 +1,2 @@
+./: cannot execute
+126
diff --git a/shell/msh_test/msh-execution/exitcode_EACCES.tests b/shell/msh_test/msh-execution/exitcode_EACCES.tests
new file mode 100755
index 000000000..26b5c6116
--- /dev/null
+++ b/shell/msh_test/msh-execution/exitcode_EACCES.tests
@@ -0,0 +1,2 @@
+./
+echo $?
diff --git a/shell/msh_test/msh-execution/exitcode_ENOENT.right b/shell/msh_test/msh-execution/exitcode_ENOENT.right
new file mode 100644
index 000000000..e2bad05e2
--- /dev/null
+++ b/shell/msh_test/msh-execution/exitcode_ENOENT.right
@@ -0,0 +1,2 @@
+./does_exist_for_sure: not found
+127
diff --git a/shell/msh_test/msh-execution/exitcode_ENOENT.tests b/shell/msh_test/msh-execution/exitcode_ENOENT.tests
new file mode 100755
index 000000000..c8866532b
--- /dev/null
+++ b/shell/msh_test/msh-execution/exitcode_ENOENT.tests
@@ -0,0 +1,2 @@
+./does_exist_for_sure
+echo $?