Strcmp generate a core dump

Question

So i have a std::unordered_map, i want to acces to strings stored intro this map. I want to search intro intro all words inside the map and compare with a given word. If the strings are same then continue execution of the if statement.

{
public:    
    bool CheckFoo(const char* word);

protected:
    typedef std::unordered_map<std::string, bool> word_map;
    word_map words_map;
};

bool CheckFoo(const char* word)
{
    if (words_map.empty())
    {
        return false;
    }

    auto it = words_map.begin();

    while (it != words_map.end())
    {
        const std::string &r = it->first;
        const char* tmp = word;

        if (strcmp(tmp, r.c_str() ) == 0)
        {
            return true;
        }
    }

    return false;
}

if (    CheckFoo("wordFoo") )
{
    //  bla bla
}

The problem is that those codes generate a .core dump file.. Do you see any mistakes in my codes?

The crash core analyze point me to strcmp line

you should check if `r == null` before `r.c_str()`, and notice that `tmp` not initialized — Dennis Vash, Nov 22 '18 at 00:16

score 3 · Accepted Answer · answered Nov 22 '18 at 00:20

Can't write comments yet but,

Like Nunchy wrote, tmp is not defined in that context. I also noticed that your code never increments the map iterator, which would result in a never ending loop.

I'm assuming you did not copy your actual code into your post but instead rewrote it hastily which resulted in some typos, but if not, try making sure you're using temp and not tmp in your call to strcmp, and make sure the loop actually increments the iterator.

Like one of the comments on your post points out as well, make sure you actually have data in the map, and the function parameter.

never increments the map iterator – Armin Nov 22 '18 at 00:34 — Armin, Nov 22 '18 at 00:34

Nunchy · Answer 2 · 2018-11-22T00:20:51.123

0

You are declaring temp then referencing tmp which doesn't exist:

    const char* temp = word;

    if (strcmp(tmp, r.c_str() ) == 0)

Does this compile? Surely it should be:

    const char* temp = word;

    if (strcmp(temp, r.c_str() ) == 0)

?

edited Nov 22 '18 at 00:20

answered Nov 22 '18 at 00:14

Nunchy

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Strcmp generate a core dump

2 Answers2