shell/ash: reimplement copy_fd as Windows does not have F_DUPFD

This implementation is quite inefficient. Looking forward to an improvement
when we manage file handle table ourselves

1 files changed, 17 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index b4e7b78a8..7cc452d20 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -4844,6 +4844,18 @@ openredirect(union node *redir)
 static int
 copyfd(int from, int to)
 {
+#ifdef __MINGW32__
+        char* fds = ckmalloc(to);
+        int i,fd;
+        memset(fds,0,to);
+        while ((fd = dup(from)) < to && fd >= 0)
+                fds[fd] = 1;
+        for (i = 0;i < to;i ++)
+                if (fds[i])
+                        close(i);
+        free(fds);
+        return fd;
+#else
         int newfd;
 
         newfd = fcntl(from, F_DUPFD, to);
@@ -4853,6 +4865,7 @@ copyfd(int from, int to)
                 ash_msg_and_raise_error("%d: %m", from);
         }
         return newfd;
+#endif
 }
 
 static void
@@ -4920,7 +4933,11 @@ redirect(union node *redir, int flags)
                 if (fd == newfd)
                         continue;
                 if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
+#ifdef __MINGW32__
+                        i = copyfd(fd, 10);
+#else
                         i = fcntl(fd, F_DUPFD, 10);
+#endif
 
                         if (i == -1) {
                                 i = errno;