Question

I’m using the function ‘strdup’ to insert a char* into a char** and getting the search.c:174:13: warning: assignment makes pointer from integer without a cast [enabled by default] warning.

char** temp;
...

temp = NULL;
...

temp[0] = strdup(tokens[i]);

Where tokens[i] is just a string from the strtok() function.

I don’t think it’s related but I have this warning as well…
search.c:174:5: warning: implicit declaration of function ‘strdup’ [-Wimplicit-function-declaration] which is only showing because I have the -ansi flag and I checked that the function was working, I just hate seeing warnings.

Also I apologize if this question was answered; there’s tons of question similar to this one but none of them helped me because from what I can tell my types are matching. (obviously not if I’m getting the warning)

Answer 1

I don’t think it’s related but I have this warning as well… search.c:174:5: warning: implicit declaration of function ‘strdup’ [-Wimplicit-function-declaration]

It is related, both have the same cause. You have no prototype for strdup in scope, so the return type is assumed to be int (in C89/C90; implicit declarations have been removed in C99, but are still widely accepted by default).

You need to #include <string.h> and enable one of the featur test macros that let strdup be defined, e.g. _XOPEN_SOURCE >= 500 or _BSD_SOURCE (and possibly even that will only work without -ansi).