libbb: new function bb_getgroups() - allocating wrapper around getgroups()

function                                             old     new   delta
bb_getgroups                                           -     111    +111
nexpr                                                843     757     -86
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/1 up/down: 111/-86)            Total: 25 bytes

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

1 files changed, 7 insertions, 26 deletions

diff --git a/coreutils/test.c b/coreutils/test.c
index edc625f57..edcf2a2d8 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -563,26 +563,11 @@ static int binop(void)
         /*return 1; - NOTREACHED */
 }
 
-
 static void initialize_group_array(void)
 {
-        int n;
-
-        /* getgroups may be expensive, try to use it only once */
-        ngroups = 32;
-        do {
-                /* FIXME: ash tries so hard to not die on OOM,
-                 * and we spoil it with just one xrealloc here */
-                /* We realloc, because test_main can be entered repeatedly by shell.
-                 * Testcase (ash): 'while true; do test -x some_file; done'
-                 * and watch top. (some_file must have owner != you) */
-                n = ngroups;
-                group_array = xrealloc(group_array, n * sizeof(gid_t));
-                ngroups = getgroups(n, group_array);
-        } while (ngroups > n);
+        group_array = bb_getgroups(&ngroups, NULL);
 }
 
-
 /* Return non-zero if GID is one that we have in our groups list. */
 //XXX: FIXME: duplicate of existing libbb function?
 // see toplevel TODO file:
@@ -610,14 +595,10 @@ static int is_a_group_member(gid_t gid)
 /* Do the same thing access(2) does, but use the effective uid and gid,
    and don't make the mistake of telling root that any file is
    executable. */
-static int test_eaccess(char *path, int mode)
+static int test_eaccess(struct stat *st, int mode)
 {
-        struct stat st;
         unsigned int euid = geteuid();
 
-        if (stat(path, &st) < 0)
-                return -1;
-
         if (euid == 0) {
                 /* Root can read or write any file. */
                 if (mode != X_OK)
@@ -625,16 +606,16 @@ static int test_eaccess(char *path, int mode)
 
                 /* Root can execute any file that has any one of the execute
                  * bits set. */
-                if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
+                if (st->st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
                         return 0;
         }
 
-        if (st.st_uid == euid)  /* owner */
+        if (st->st_uid == euid)  /* owner */
                 mode <<= 6;
-        else if (is_a_group_member(st.st_gid))
+        else if (is_a_group_member(st->st_gid))
                 mode <<= 3;
 
-        if (st.st_mode & mode)
+        if (st->st_mode & mode)
                 return 0;
 
         return -1;
@@ -667,7 +648,7 @@ static int filstat(char *nm, enum token mode)
                         i = W_OK;
                 if (mode == FILEX)
                         i = X_OK;
-                return test_eaccess(nm, i) == 0;
+                return test_eaccess(&s, i) == 0;
         }
         if (is_file_type(mode)) {
                 if (mode == FILREG)