columnNames[i] = malloc(strlen(buffer) + 1); Need to deal with that pesky '\0'!
-----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Stephen Wood Sent: Thursday, May 31, 2012 11:47 AM To: sqlite-users@sqlite.org Subject: [sqlite] Segmentation Fault when calling sqlite3_finalize Hello all, I'm having some memory allocation difficulties while using the SQLite C API. The goal of the function that is currently giving me issues is just trying to read the column names from a table. I have been having other memory allocation faults elsewhere, but I currently have it isolated to this particular section of code (I say this because I suppose the root problem could be elsewhere in my code). Also strangely enough, if I do not store the data returned from sqlite3_column_name, but instead just print it to stdout, I do not get a segmentation fault, which also leads to me thinking my error may be more fundamental... This function is also run multiple times and only produces segmentation faults on the third table I run it on. I am using the database here<http://download.codeplex.com/Download/Release?ProjectName=chinookdatabase&DownloadId=167067&FileTime=129342699263670000&Build=18924>for testing. Please let me know if I can provide any more relevant information. Any help would be greatly appreciated. Below is the relevant code segment. Thanks! char **getColumnNames(char **columnNames, sqlite3 *database, char *tableName) { sqlite3_stmt *statement = NULL; char sqlStatementString[100]; char *sqlErrorMessage = 0; char buffer[100]; int status = 0; int i = 0; int numOfCols = 0; // Prepare a statement to get the tables from the database sprintf(sqlStatementString, "SELECT * FROM '%s';", tableName); status = sqlite3_prepare_v2(database, sqlStatementString, strlen(sqlStatementString), &statement, NULL); if (status != SQLITE_OK) { fprintf(stderr, "Error occured when attempting to prepare an SQL statement\n" "Error:%s\n", sqlErrorMessage); // Prevents memory leaking from error message: sqlite3_free(sqlErrorMessage); exit(1); } // end error check // I only want the first row, because I am only getting the names // for the columns. This is why I only run the step function once if (sqlite3_step(statement) != SQLITE_ROW) { fprintf(stderr, "Either an error occured or table \"%s\" has no data!\n", tableName); exit(1); } numOfCols = sqlite3_column_count(statement); if (numOfCols < 1) { perror("No columns in that table!\n"); exit(1); } columnNames = (char **) malloc(numOfCols * sizeof(char *)); if (columnNames == NULL) { perror("Allocation error: "); exit(1); } // end error check for malloc for (i = 0; i < numOfCols; i++) { sprintf(buffer, "%s", (char *) sqlite3_column_name(statement, i)); columnNames[i] = malloc(strlen(buffer)); if (columnNames[i] == NULL) { perror("Failed to allocate memory for a column name\n"); exit(1); } // end malloc error check strcpy(columnNames[i], buffer); } // end column loop // Destroy the statement // ******** THIS IS WHERE I GET THE SEGMENTATION FAULT ********** status = sqlite3_finalize(statement); if (status != SQLITE_OK) { fprintf(stderr, "Error occured when attempting to destroy a SQL statement\n" "Error:%s\n", sqlErrorMessage); // Prevents memory leaking from error message: sqlite3_free(sqlErrorMessage); exit(1); } // end error check return columnNames; } // end of function -- Stephen Wood RMCI, INC. 1525 Perimeter Parkway Suite 430 Huntsville, AL 35806** ** _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
