run.c - arg parse fix

Fixes segfault when last parameter is missing

.gitignore

@@ -3,3 +3,4 @@ out/model.bin
 run
 run.com.dbg
 run.com
+a.out

run.c

@@ -527,12 +527,12 @@ int main(int argc, char *argv[]) {
         switch (argv[i][0]) {
             case '-':
                 switch (argv[i][1]) {
-                    case 'c': checkpoint = argv[++i];		break;
-                    case 't': temperature = atof(argv[++i]);	break;
-                    case 's': steps = atoi(argv[++i]);		break;
-                    case 'b': buffertokens = atoi(argv[++i]);	break;
-                    case 'p': prompt = argv[++i];		break;
-                    default: printf("Invalid option: %s\n", argv[i]);
+                    case 'c': if (i + 1 < argc) { checkpoint = argv[++i]; }             break;
+                    case 't': if (i + 1 < argc) { temperature = atof(argv[++i]); }	break;
+                    case 's': if (i + 1 < argc) { steps = atoi(argv[++i]); }            break;
+                    case 'b': if (i + 1 < argc) { buffertokens = atoi(argv[++i]);}      break;
+                    case 'p': if (i + 1 < argc) { prompt = argv[++i]; }                 break;
+                    default: printf("Invalid option: %s\n", argv[i]); 
                     exit(EXIT_FAILURE);
                 } break;
             default:
@@ -620,11 +620,10 @@ int main(int argc, char *argv[]) {
     int token = 1;   // init with token 1 (=BOS), as done in Llama-2 sentencepiece tokenizer
     int pos = 0;     // position in the sequence
     int bufferflush = 1; // buffer flush after token counter 
-    #define MAX_BUFFER_SIZE 4096 // max buffer size
-    char outbuff[MAX_BUFFER_SIZE]=""; // used for output buffering
-    memset( outbuff, '\0', sizeof( outbuff )); // clear buffer area
+    #define BUFFER_SIZE 4096 // max buffer size
+    static char outbuff[BUFFER_SIZE]; // used for output buffering
     printf("<s>\n"); // explicit print the initial BOS token for stylistic symmetry reasons
-    setvbuf(stdout, outbuff, _IOFBF, MAX_BUFFER_SIZE); // setup output buffering
+    setvbuf(stdout, outbuff, _IOFBF, BUFFER_SIZE); // setup output buffering
     while (pos < steps) {
 
         // forward the transformer to get logits for the next token
@@ -652,7 +651,7 @@ int main(int argc, char *argv[]) {
         char *token_str = (token == 1 && vocab[next][0] == ' ') ? vocab[next]+1 : vocab[next];
 
         printf("%s", token_str);
-        if (bufferflush==pos && strlen(outbuff)<=MAX_BUFFER_SIZE) { fflush(stdout); bufferflush+=buffertokens; } // flush after every n tokens
+        if (bufferflush==pos && strlen(outbuff)<=BUFFER_SIZE) { fflush(stdout); bufferflush+=buffertokens; } // flush after every n tokens
 
         // advance forward
         token = next;