Detect and execute shell scripts based on presence of '#!'

1 files changed, 13 insertions, 2 deletions

diff --git a/shell/ash.c b/shell/ash.c
index a446a6699..109473b97 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -21,7 +21,9 @@
  *
  * - Environment variables from Windows will all be turned to uppercase.
  * - PATH accepts both ; and : as separator, but can't be mixed
- * - command without ".exe" is still understood as executable (option to turn off?)
+ * - command without ".exe" extension is still understood as executable
+ * - shell scripts on the path are detected by the presence of '#!';
+ *   the path to the interpreter is ignored, PATH is searched to find it
  * - both / and \ are supported in PATH. Usually you must use /
  * - trap/job does not work
  * - /dev/null is supported for redirection
@@ -12951,7 +12953,16 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
                                 if (stat(fullname, &statb) < 0) {
                                         if (errno != ENOENT && errno != ENOTDIR)
                                                 e = errno;
-                                        goto loop;
+                                        fullname[len] = '\0';
+                                        if (stat(fullname, &statb) < 0) {
+                                                if (errno != ENOENT && errno != ENOTDIR)
+                                                        e = errno;
+                                                goto loop;
+                                        }
+                                        if (!execable_file(fullname)) {
+                                                e = ENOEXEC;
+                                                goto loop;
+                                        }
                                 }
                         }
                         fullname[len] = '\0';