Compilare: user.c: In function ‘hasAlphanumerical’: user.c:10:5: warning: implicit declaration of function ‘isalnum’ [-Wimplicit-function-declaration] if (isalnum(*s)) ^ user.c: In function ‘adjust’: user.c:19:2: warning: implicit declaration of function ‘isdigit’ [-Wimplicit-function-declaration] while(!isdigit(*s) && *s != '"') ^ user.c:35:3: warning: implicit declaration of function ‘calloc’ [-Wimplicit-function-declaration] char *number = calloc(2*strlen(s), 1); ^ user.c:35:18: warning: incompatible implicit declaration of built-in function ‘calloc’ [enabled by default] char *number = calloc(2*strlen(s), 1); ^ user.c:41:5: warning: statement with no effect [-Wunused-value] number[count] == '\0'; ^ user.c: In function ‘main’: user.c:57:5: warning: implicit declaration of function ‘strdup’ [-Wimplicit-function-declaration] keys[0] = strdup(""); ^ user.c:57:13: warning: assignment makes pointer from integer without a cast [enabled by default] keys[0] = strdup(""); ^ user.c:75:41: warning: assignment makes pointer from integer without a cast [enabled by default] keys[index / 2] = strdup(token); ^ user.c:81:43: warning: assignment makes pointer from integer without a cast [enabled by default] values[index / 2 - 1] = strdup(token); ^ user.c:52:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("convertor.in", "r", stdin); ^ user.c:53:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("convertor.out", "w", stdout); ^