libbb: improve stripping of extension from argv[0]

Use library routines to reduce the amount of code needed to strip
the extension from argv[0] in the BusyBox main function.

The name of the executable can now have any of the standard
extensions, none at all, or a trailing dot.

Related to GitHub issue #20.

1 files changed, 11 insertions, 15 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 491eb4208..210f9ff4d 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -1142,24 +1142,20 @@ int main(int argc UNUSED_PARAM, char **argv)
         applet_name = argv[0];
         if (applet_name[0] == '-')
                 applet_name++;
-        if (ENABLE_PLATFORM_MINGW32) {
-                if ( argv[1] && argv[2] && strcmp(argv[1], "--busybox") == 0 ) {
-                        argv += 2;
-                        applet_name = argv[0];
-                }
-                else {
-                        char *s = argv[0];
-                        int i, len = strlen(s);
+# if ENABLE_PLATFORM_MINGW32
+        if ( argv[1] && argv[2] && strcmp(argv[1], "--busybox") == 0 ) {
+                argv += 2;
+                applet_name = argv[0];
+        }
+        else {
+                char *s;
 
-                        for ( i=0; i < len; ++i ) {
-                                s[i] = tolower(s[i]);
-                        }
-                        if (len > 4 && !strcmp(s+len-4, ".exe")) {
-                                len -= 4;
-                                s[len] = '\0';
-                        }
+                str_tolower(argv[0]);
+                if (has_exe_suffix_or_dot(argv[0]) && !(s=strrchr(argv[0], '.'))) {
+                        *s = '\0';
                 }
         }
+# endif
         applet_name = bb_basename(applet_name);
 
         /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */