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POFreeing memory allocated by strdup
 

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    <p>How would I free the memory allocated by strdup? I've tried using free(linepos) at the end of this function, but that causes my program to fail. I don't have linepos outside of this function, so I'm unable to free it anywhere else. Thank you in advance.</p> <pre><code>void putinqueue (queue *the_queue, FILE *input, char *filename) { char buffer[1024]; for (int linenr = 1; ; ++linenr) { char *linepos = fgets (buffer, sizeof buffer, input); if (linepos == NULL) break; linepos = strchr (buffer, '\n'); if (linepos == NULL) { fflush (NULL); fprintf (stderr, "%s: %s[%d]: unterminated line\n", execname, filename, linenr); fflush (NULL); exit_status = EXIT_FAILURE; }else { *linepos = '\0'; } linepos = strdup (buffer); assert (linepos != NULL); insert_queue (the_queue, linepos); } } </code></pre> <p>EDIT: Here are the other functions. Sorry, copy and pasted the old source. This is the new one.</p> <pre><code>void insert_queue (queue *this, queue_item_t item) { //Inserts a new item at the end of queue. queue_node *temp = malloc(sizeof (struct queue_node)); temp-&gt;item = item; temp-&gt;link = NULL; if (isempty_queue(this)) this-&gt;front = temp; else this-&gt;rear-&gt;link = temp; this-&gt;rear = temp; } queue_item_t remove_queue (queue *this) { //This removes the first item from queue. assert (! isempty_queue (this)); //Creates temp, and rVal and initializes them. queue_node *temp = this-&gt;front; queue_item_t rVal = temp-&gt;item; //Moves on to the next one. this-&gt;front = this-&gt;front-&gt;link; if (this-&gt;front == NULL) this-&gt;rear = NULL; //Free the unlinked node. free(temp); temp = NULL; return rVal; } </code></pre>
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    1. USMickey
    1. USMickey
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      1. VTUpMod
    1. CO"The returned pointer can be passed to free()" http://pubs.opengroup.org/onlinepubs/009696799/functions/strdup.html. Your issue is more likely about what `insert_queue` is doing. If it isn't making its own copy, then you're freeing memory which is still being used by the queue (and should more rightly become the queue's responsibility to free).
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      1. USDave
    2. COYou're putting the pointer into your queue; you should `free` the memory when you delete the queue explicitly. If you aren't, you will have to start.
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      1. USJoe
    3. COIs queue_item a typedef of a char * if not wtf are you doing?
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      1. USScotty Bauer
 

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