Return the number of tokens given a command

C Program Return the number of tokens given a command

/* in setup_stack()... */
int i = 0;
int argc = get_argc(file_name);
char *token, *save_ptr;
char **argv = malloc((argc + 1) * sizeof(char *));
size_t token_size;
//generate argv and push args onto stack
for (token = strtok_r((char *)file_name, " ", &save_ptr); token != NULL; token = strtok_r(NULL, " ", &save_ptr)) {
token_size = strlen(token) + 1;
*esp = *esp - token_size;
argv[i] = *esp;
i++;
memcpy(*esp, token, token_size);
} argv[argc] = 0;
//perform alignment
size_t alignment = (size_t) *esp % 4;
if (alignment) {
*esp = *esp - alignment;
memcpy(*esp, &argv[argc], alignment);
}
//push argv pointers
for (i = argc; i >= 0; i--) {
*esp = *esp - sizeof(char *);
memcpy(*esp, &argv[i], sizeof(char *));
}
//push pointer to argv
char *ptr = *esp;
*esp = *esp - sizeof(char **);
memcpy(*esp, &ptr, sizeof(char **));
//push argc
*esp = *esp - sizeof(int);
memcpy(*esp, &argc, sizeof(int));
//push dummy return address
*esp = *esp - sizeof(void *);
memcpy(*esp, &argv[argc], sizeof(void *));
free(argv);
return success;
}
/* Return the number of tokens given a command 'file_name.' */
int get_argc(const char* file_name) {
int argc = 0;
char *buffer, *token, *save_ptr;
buffer = malloc(sizeof(file_name));
strlcpy(buffer, file_name, sizeof(file_name));
for (token = strtok_r((char *)buffer, " ", &save_ptr); token != NULL; token = strtok_r(NULL, " ", &save_ptr)) {
argc++;
}
free(buffer);
return argc;
}

Return

Number

given

Argument

Command

Token

Stack

NAIMCPROGRAM