libbb: modify find_executable() to not temporarily write to PATH

This allows to simplify "which" applet code

function                                             old     new   delta
find_executable                                       93     111     +18
which_main                                           191     177     -14
builtin_source                                       316     294     -22
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 18/-36)            Total: -18 bytes

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

1 files changed, 3 insertions, 6 deletions

diff --git a/debianutils/which.c b/debianutils/which.c
index 1f547919f..a7d55a215 100644
--- a/debianutils/which.c
+++ b/debianutils/which.c
@@ -31,15 +31,12 @@
 int which_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int which_main(int argc UNUSED_PARAM, char **argv)
 {
-        char *env_path;
+        const char *env_path;
         int status = 0;
-        /* This sizeof(): bb_default_root_path is shorter than BB_PATH_ROOT_PATH */
-        char buf[sizeof(BB_PATH_ROOT_PATH)];
 
         env_path = getenv("PATH");
         if (!env_path)
-                /* env_path must be writable, and must not alloc, so... */
-                env_path = strcpy(buf, bb_default_root_path);
+                env_path = bb_default_root_path;
 
         getopt32(argv, "^" "a" "\0" "-1"/*at least one arg*/);
         argv += optind;
@@ -54,7 +51,7 @@ int which_main(int argc UNUSED_PARAM, char **argv)
                                 puts(*argv);
                         }
                 } else {
-                        char *path;
+                        const char *path;
                         char *p;
 
                         path = env_path;