As I learn C, I decided to write a small dictionary program, for my linux box. Unfortunatly, I'm unable to proceed because of that weird bug which I can't debug (no source of crash). Any help is appreciated. strace: read(3, "\270) file box\n 3) \321\200\320\260\320\267\320\263. \320\277\321\200\320\265"..., 4096) = 4096 read(3, "mixture of vodka and beer\n", 4096) = 26 read(3, "", 4096) = 0 close(3) = 0 munmap(0xb7860000, 4096) = 0 write(4, "\320\275\320\276-\320\266\321\221\320\273\321\202\321\213\320\271@11618255\n\321\217\320\270\321"..., 3875) = 3875 close(4) = 0 munmap(0xb785f000, 4096) = 0 --- SIGSEGV (Segmentation fault) @ 0 (0) --- +++ killed by SIGSEGV +++ gdb: Program received signal SIGSEGV, Segmentation fault. 0x80d15d70 in ?? () valgrind: ==11809== Memcheck, a memory error detector ==11809== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al. ==11809== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright info ==11809== Command: ./dic -u ==11809== Parent PID: 1662 ==11809== ==11809== Jump to the invalid address stated on the next line ==11809== at 0x80D15D70: ??? ==11809== Address 0x80d15d70 is not stack'd, malloc'd or (recently) free'd ==11809== ==11809== ==11809== Process terminating with default action of signal 11 (SIGSEGV) ==11809== Access not within mapped region at address 0x80D15D70 ==11809== at 0x80D15D70: ??? ==11809== If you believe this happened as a result of a stack ==11809== overflow in your program's main thread (unlikely but ==11809== possible), you can try to increase the size of the ==11809== main thread stack using the --main-stacksize= flag. ==11809== The main thread stack size used in this run was 8388608. ==11809== ==11809== HEAP SUMMARY: ==11809== in use at exit: 70 bytes in 2 blocks ==11809== total heap usage: 426,629 allocs, 426,627 frees, 224,953,822 bytes allocated ==11809== ==11809== LEAK SUMMARY: ==11809== definitely lost: 70 bytes in 2 blocks ==11809== indirectly lost: 0 bytes in 0 blocks ==11809== possibly lost: 0 bytes in 0 blocks ==11809== still reachable: 0 bytes in 0 blocks ==11809== suppressed: 0 bytes in 0 blocks ==11809== Rerun with --leak-check=full to see details of leaked memory ==11809== ==11809== For counts of detected and suppressed errors, rerun with: -v ==11809== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 20 from 7)