ash: if tcgetattr(stdin) fails, don't mess with tcsetattr

ash: size-optimize ulimit's table of limits

   text    data     bss     dec     hex filename
 777345     974    9676  787995   c061b busybox_old
 777253     974    9676  787903   c05bf busybox_unstripped

diff --git a/shell/ash.c b/shell/ash.c
index 58527bf9b28f8c941fc80311079edf0d8e3978a5..bb930f55fbb31555d2e9d277e4c773f3f6299282 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11575,26 +11575,31 @@ readcmd(int argc, char **argv)
                ifs = defifs;
 #if ENABLE_ASH_READ_NCHARS
        if (n_flag || silent) {
-               tcgetattr(0, &tty);
-               old_tty = tty;
-               if (n_flag) {
-                       tty.c_lflag &= ~ICANON;
-                       tty.c_cc[VMIN] = nchars;
-               }
-               if (silent) {
-                       tty.c_lflag &= ~(ECHO|ECHOK|ECHONL);
+               if (tcgetattr(0, &tty) != 0) {
+                       /* Not a tty */
+                       n_flag = 0;
+                       silent = 0;
+               } else {
+                       old_tty = tty;
+                       if (n_flag) {
+                               tty.c_lflag &= ~ICANON;
+                               tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
+                       }
+                       if (silent) {
+                               tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
+                       }
+                       tcsetattr(0, TCSANOW, &tty);
                }
-               tcsetattr(0, TCSANOW, &tty);
        }
 #endif
 #if ENABLE_ASH_READ_TIMEOUT
        if (ts.tv_sec || ts.tv_usec) {
-// TODO: replace with poll, it is smaller
                FD_ZERO(&set);
                FD_SET(0, &set);
 
-               i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
-               if (!i) {
+               /* poll-based wait produces bigger code, using select */
+               i = select(1, &set, NULL, NULL, &ts);
+               if (!i) { /* timed out! */
 #if ENABLE_ASH_READ_NCHARS
                        if (n_flag)
                                tcsetattr(0, TCSANOW, &old_tty);
@@ -11742,48 +11747,81 @@ umaskcmd(int argc, char **argv)
  */
 
 struct limits {
-       const char *name;
-       int     cmd;
-       int     factor; /* multiply by to get rlim_{cur,max} values */
+       uint8_t cmd;          /* RLIMIT_xxx fit into it */
+       uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
        char    option;
 };
 
-static const struct limits limits[] = {
+static const struct limits limits_tbl[] = {
 #ifdef RLIMIT_CPU
-       { "time(seconds)",              RLIMIT_CPU,        1, 't' },
+       { RLIMIT_CPU,        0, 't' },
 #endif
 #ifdef RLIMIT_FSIZE
-       { "file(blocks)",               RLIMIT_FSIZE,    512, 'f' },
+       { RLIMIT_FSIZE,      9, 'f' },
 #endif
 #ifdef RLIMIT_DATA
-       { "data(kbytes)",               RLIMIT_DATA,    1024, 'd' },
+       { RLIMIT_DATA,      10, 'd' },
 #endif
 #ifdef RLIMIT_STACK
-       { "stack(kbytes)",              RLIMIT_STACK,   1024, 's' },
+       { RLIMIT_STACK,     10, 's' },
 #endif
-#ifdef  RLIMIT_CORE
-       { "coredump(blocks)",           RLIMIT_CORE,     512, 'c' },
+#ifdef RLIMIT_CORE
+       { RLIMIT_CORE,       9, 'c' },
 #endif
 #ifdef RLIMIT_RSS
-       { "memory(kbytes)",             RLIMIT_RSS,     1024, 'm' },
+       { RLIMIT_RSS,       10, 'm' },
 #endif
 #ifdef RLIMIT_MEMLOCK
-       { "locked memory(kbytes)",      RLIMIT_MEMLOCK, 1024, 'l' },
+       { RLIMIT_MEMLOCK,   10, 'l' },
 #endif
 #ifdef RLIMIT_NPROC
-       { "process",                    RLIMIT_NPROC,      1, 'p' },
+       { RLIMIT_NPROC,      0, 'p' },
 #endif
 #ifdef RLIMIT_NOFILE
-       { "nofiles",                    RLIMIT_NOFILE,     1, 'n' },
+       { RLIMIT_NOFILE,     0, 'n' },
 #endif
 #ifdef RLIMIT_AS
-       { "vmemory(kbytes)",            RLIMIT_AS,      1024, 'v' },
+       { RLIMIT_AS,        10, 'v' },
 #endif
 #ifdef RLIMIT_LOCKS
-       { "locks",                      RLIMIT_LOCKS,      1, 'w' },
+       { RLIMIT_LOCKS,      0, 'w' },
 #endif
-       { NULL,                         0,                 0,  '\0' }
 };
+static const char limits_name[] =
+#ifdef RLIMIT_CPU
+       "time(seconds)" "\0"
+#endif
+#ifdef RLIMIT_FSIZE
+       "file(blocks)" "\0"
+#endif
+#ifdef RLIMIT_DATA
+       "data(kb)" "\0"
+#endif
+#ifdef RLIMIT_STACK
+       "stack(kb)" "\0"
+#endif
+#ifdef RLIMIT_CORE
+       "coredump(blocks)" "\0"
+#endif
+#ifdef RLIMIT_RSS
+       "memory(kb)" "\0"
+#endif
+#ifdef RLIMIT_MEMLOCK
+       "locked memory(kb)" "\0"
+#endif
+#ifdef RLIMIT_NPROC
+       "process" "\0"
+#endif
+#ifdef RLIMIT_NOFILE
+       "nofiles" "\0"
+#endif
+#ifdef RLIMIT_AS
+       "vmemory(kb)" "\0"
+#endif
+#ifdef RLIMIT_LOCKS
+       "locks" "\0"
+#endif
+;
 
 enum limtype { SOFT = 0x1, HARD = 0x2 };
 
@@ -11800,7 +11838,7 @@ printlim(enum limtype how, const struct rlimit *limit,
        if (val == RLIM_INFINITY)
                out1fmt("unlimited\n");
        else {
-               val /= l->factor;
+               val >>= l->factor_shift;
                out1fmt("%lld\n", (long long) val);
        }
 }
@@ -11866,8 +11904,8 @@ ulimitcmd(int argc, char **argv)
                        what = optc;
                }
 
-       for (l = limits; l->option != what; l++)
-               ;
+       for (l = limits_tbl; l->option != what; l++)
+               continue;
 
        set = *argptr ? 1 : 0;
        if (set) {
@@ -11887,13 +11925,15 @@ ulimitcmd(int argc, char **argv)
                        }
                        if (c)
                                ash_msg_and_raise_error("bad number");
-                       val *= l->factor;
+                       val <<= l->factor_shift;
                }
        }
        if (all) {
-               for (l = limits; l->name; l++) {
+               const char *lname = limits_name;
+               for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
                        getrlimit(l->cmd, &limit);
-                       out1fmt("%-20s ", l->name);
+                       out1fmt("%-20s ", lname);
+                       lname += strlen(lname) + 1;
                        printlim(how, &limit, l);
                }
                return 0;