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>

diff --git a/shell/ash.c b/shell/ash.c
index 2669157bcae1aed3e5502690db8b08a52c328a24..80dfc1d6aa76579bdcc9e5c674bac7c41656219d 100644 (file)
--- 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);