when run program system crash "segmentation fault" message.
i want know if there way know instruction (code line) caused system crash segmentation fault message"
code ===>
#include "geoip.h" int main() { file *f; char ipaddress[30]; char expectedcountry[3]; char expectedcountry3[4]; const char *returnedcountry; geoip *gi; int failed = 0; int test_num = 1; int i; (i = 0; < 2; ++i) { if (0 == i) { /* read filesystem, check updated file */ gi = geoip_open("/usr/share/geoip/geoip.dat", geoip_standard | geoip_check_cache); } else { /* read memory, faster takes more memory */ gi = geoip_open("/usr/share/geoip/geoip.dat", geoip_memory_cache); } if (gi == null) { fprintf(stderr, "error opening database\n"); exit(1); } /* make sure geoip deals invalid query gracefully */ returnedcountry = geoip_country_code_by_addr(gi, null); if (returnedcountry != null) { fprintf(stderr, "invalid query test failed, got non null, expected null\n"); failed = 1; } returnedcountry = geoip_country_code_by_name(gi, null); if (returnedcountry != null) { fprintf(stderr, "invalid query test failed, got non null, expected null\n"); failed = 1; } f = fopen("/home/aa/test/country_test.txt", "r"); while (fscanf(f, "%s%s%s", ipaddress, expectedcountry, expectedcountry3) != eof) { returnedcountry = geoip_country_code_by_addr(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry) != 0) { fprintf(stderr, "test addr %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } returnedcountry = geoip_country_code_by_name(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry) != 0) { fprintf(stderr, "test name %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } returnedcountry = geoip_country_code3_by_addr(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry3) != 0) { fprintf(stderr, "test addr %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } returnedcountry = geoip_country_code3_by_name(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry3) != 0) { fprintf(stderr, "test name %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } test_num++; } fclose(f); f = fopen( "/home/aa/test/country_test2.txt", "r"); while (fscanf(f, "%s%s", ipaddress, expectedcountry) != eof) { returnedcountry = geoip_country_code_by_addr(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry) != 0) { fprintf(stderr, "test addr %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } test_num++; } fclose(f); f = fopen( "/home/aa/test/country_test_name.txt", "r"); while (fscanf(f, "%s%s", ipaddress, expectedcountry) != eof) { returnedcountry = geoip_country_code_by_name(gi, ipaddress); if (returnedcountry == null || strcmp(returnedcountry, expectedcountry) != 0) { fprintf(stderr, "test addr %d %s failed, got %s, expected %s\n", test_num, ipaddress, returnedcountry, expectedcountry); failed = 1; } test_num++; } fclose(f); geoip_delete(gi); } return failed; } thanks
as many people stated: use debugger or tool valgrind.
however might source of problems (i've stripped non-interesting parts):
if (returnedcountry == null || ...) { fprintf(stderr, ".. %s ..\n", returnedcountry...); ... } there several instances this. have fopen calls don't check return value. always that.
Comments
Post a Comment