Thank you! I can't believe I missed that! On Thu, May 31, 2012 at 10:50 AM, Marc L. Allen <[email protected] > wrote:
> columnNames[i] = malloc(strlen(buffer) + 1); > > Need to deal with that pesky '\0'! > > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Stephen Wood > Sent: Thursday, May 31, 2012 11:47 AM > To: [email protected] > 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 > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- Stephen Wood RMCI, INC. 1525 Perimeter Parkway Suite 430 Huntsville, AL 35806** ** _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
