Return structure pointer in C

Question

Could you please help me in correcting my code:

This is a function that returns a pointer to struct item:

struct item* findItem(const char* key) {
    for (int i = 0; i < nItems; i++) {
        if (!strcmp(items[i].key, key)) { return &items[i]; }
    }
    return NULL;
}

From main function, I want to retrieve my struct value as following:

struct item search_items = findItem(&key) ; // I have problem with this line 
char* itemValue;
if (search_items != NULL)
{
    itemValue = search_items->value;
}

How can I retrieve the structure and save it to be used in the main function?

In addition to the answer(s) below: consider what is going to happen to itemValue if findItem returns NULL. — Jabberwocky
– Jabberwocky, Commented Mar 31, 2017 at 10:15
i can not post the code because it is part of socket programming assignment and if someone copied the same code i will get zero mark — Rabab Alkhalifa
– Rabab Alkhalifa, Commented Mar 31, 2017 at 12:00

unalignedmemoryaccess · Accepted Answer · 2017-03-31 09:55:34Z

4

If you are returning pointer from function, then you have to read it as pointer. Notice struct item* search_items part on my code and on your (I added pointer *)

struct item* search_items = findItem(&key) ; // i have problem with this line 
char* itemValue;
if ( search_items != NULL)
{
    itemValue = search_items->value;
}

answered Mar 31, 2017 at 9:55

unalignedmemoryaccess

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5 Comments

Rabab Alkhalifa Over a year ago

yes i did the same and it worked + also i removed &key and pass key only .. it now executed but i always get an empty value from search_items

unalignedmemoryaccess Over a year ago

Well, does your string exist? The code has been properly corrected. Now it is up to you to either show more code, what key is or similar.

Rabab Alkhalifa Over a year ago

how can i access to the memory to check weather the struct is stored correctly or not ?

unalignedmemoryaccess Over a year ago

I don't know what exactly you want to do so I don't have an answer.

Rabab Alkhalifa Over a year ago

using gdb debugger solved my issue .. apperently i was not saving the struct using memcpy command and i was losing my data.

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