defrag.cpp: In function 'int main()': defrag.cpp:16: warning: statement has no effect defrag.cpp:27: warning: statement has no effect defrag.cpp:14: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result defrag.cpp:17: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result defrag.cpp:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result