ash: shrink "umask -S" code

function                                             old     new   delta
umaskcmd                                             279     286      +7
static.permmode                                        3       -      -3
static.permmask                                       18       -     -18

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 14 insertions, 17 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 2669157bc..80dfc1d6a 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -12816,16 +12816,9 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 static int FAST_FUNC
 umaskcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
-        static const char permuser[3] ALIGN1 = "ugo";
-        static const char permmode[3] ALIGN1 = "rwx";
-        static const short permmask[] ALIGN2 = {
-                S_IRUSR, S_IWUSR, S_IXUSR,
-                S_IRGRP, S_IWGRP, S_IXGRP,
-                S_IROTH, S_IWOTH, S_IXOTH
-        };
+        static const char permuser[3] ALIGN1 = "ogu";
 
         mode_t mask;
-        int i;
         int symbolic_mode = 0;
 
         while (nextopt("S") != '\0') {
@@ -12839,22 +12832,26 @@ umaskcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 
         if (*argptr == NULL) {
                 if (symbolic_mode) {
-                        char buf[18];
+                        char buf[sizeof("u=rwx,g=rwx,o=rwx")];
                         char *p = buf;
+                        int i;
 
-                        for (i = 0; i < 3; i++) {
-                                int j;
+                        i = 2;
+                        for (;;) {
+                                unsigned bits;
 
                                 *p++ = permuser[i];
                                 *p++ = '=';
-                                for (j = 0; j < 3; j++) {
-                                        if ((mask & permmask[3 * i + j]) == 0) {
-                                                *p++ = permmode[j];
-                                        }
-                                }
+                                /* mask is 0..0uuugggooo. i=2 selects uuu bits */
+                                bits = (mask >> (i*3));
+                                if (!(bits & 4)) *p++ = 'r';
+                                if (!(bits & 2)) *p++ = 'w';
+                                if (!(bits & 1)) *p++ = 'x';
+                                if (--i < 0)
+                                        break;
                                 *p++ = ',';
                         }
-                        *--p = '\0';
+                        *p = '\0';
                         puts(buf);
                 } else {
                         out1fmt("%.4o\n", mask);