Comparing buffer with a C String [duplicate]

This question already has answers here开发者_运维技巧: Closed 10 years ago.

Possible Duplicate:

How to compare pointer to strings in C

How to compare the characters in a buffer with a string?

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By buffer, I assume its not NULL terminated. Then you can not use strcmp, instead you can use strncmp.

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Assuming, the buffer is an array of characters. You can compare character by character. Example -

char buffer[] = { 'a','b','c' };
char* str = "b";

int i=0;
while( i<3 )
{
    if( buffer[i] == *str )
        printf("\n Equal \n" );
    else
        printf("\n Not Equal \n" );

    ++i;
}

The above code should give you basic idea of how to implement. Results : IdeOne

Things you need to think of to answer the question -

• What if the value pointed by str is "abc"?
• What if the entire buffer needs to be compared to value pointed by char* ( i.e., buffer is equal to value pointed by char* ?

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Something that throws a lot of people off at first is that strcmp returns 0 if the strings match, so you usually use something like if (!strcmp(buffer, "change"))

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int strcmp ( const char *s1, const char *s2 );

Try this. It will help you.