win32: implement umask(2)

umask() in the Microsoft C runtime takes different arguments to
umask(2).  Implement a fake umask(2) that remembers the mask and
calls the Microsoft umask() with an appropriate value.

Since the mask won't be inherited by children use an environment
variable to pass any value set by the shell built-in umask.

1 files changed, 9 insertions, 0 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 8a66b3303..ba52ef581 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -1081,6 +1081,15 @@ void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **ar
         applet_name = name;
 #if ENABLE_PLATFORM_MINGW32
         strcpy(bb_applet_name, applet_name);
+
+        {
+                const char *vmask;
+                unsigned int mask;
+
+                vmask = getenv("BB_UMASK");
+                if (vmask && sscanf(vmask, "%o", &mask) == 1)
+                        umask((mode_t)(mask&0777));
+        }
 #endif
 
         /* Special case. POSIX says "test --help"