Thread: warning: Incompatible integer to pointer conversion assigning to 'char *' to int

Hi all, when I use the function to concat the pointer, the warning message is come out (Incompatible integer to pointer conversion assigning to 'char *' to 'int'), how can I fix this, many thanks!!

Code:

char* concat(char* left,char* right)
{
    char* all = malloc(strlen(left)+strlen(right)+1);
    strcpy(all, left);
    strcat(all, right);
    puts(all);
    free(all);
    return all;
}

//use the concat function like this:
char* all;
char* tmp="abc";
all = concat("06",tmp); //warning msg here "sc means concat"

I notice that you are calling a mysterious function named sc, not your concat function.

Besides this, there is the issue that you called strcpy before initialising what all points to, i.e.,

Code:

all[0] = '\0';

should have come before the strcpy call. You should also check that malloc did not return a null pointer.

Then, it makes no sense to free(all) then return all; Perhaps you should free in the caller instead.

Oh, and since you are not modifying what left and right point to, you should declare them to be const char* instead.

> should have come before the strcpy call. You should also check that malloc did not return a null pointer.
strcpy does not depend on the initial contents of the destination (whereas strcat does).