Question

Im using strtok and getting a little confused.

I have an array holding a lot of strings and I want to tokenize the strings into a temporary array. When i perform the strtok it stored the first token in the temporary array, but also changed the original arrays value. So im pretty confused.

char cmdTok[10] , *cmd = cmdTok;
printf("command[0] = %s\n", commands[0]);
cmd = strtok(commands[0], " \n\0");
printf("command[0] after strtok = %s\n", commands[0]);

Output being

command[0] = #Draw A Ring
command[0] after strtok = #draw

How do i retain the original values in command?

Answer 1

Do the strtok on a copy of the string.

char *copy = strdup(commands[0]);
cmd = strtok(copy, " \n");
/* ... */

free(copy);

If you don’t have / want to use strdup:

char *copy = malloc(strlen(commands[0]) + 1);
strcpy(copy, commands[0]);
/* ... */