Using Emacs 23.2.1 on Ubuntu Lucid, any mode based on Comint inserts occasional line breaks for larger outputs (see example Shell and SQL mode output, below). I’ve tried this in both SQL Mode and Shell Mode, with the same result in either case. Running similar commands in a plain terminal emulator does not cause these problems (for both shell mode and mysql mode commands).
Things I have tried:
-
Using MySQL in SQL Mode, adding the following flags: -A, -C, -t, -f, -n, and setting max_allowed_packet to 16MB.
-
Setting comint-buffer-maximum-size to 10240.
None of these have any effect on this behavior.
If I scroll up to the lines in question and delete the line breaks, the output then appears correctly, so a possible solution to this problem could involve a hook that deletes every 4096th character, if such a thing is possible.
Note: In the terminal examples, the output appears to be cut off at points other than every 4096 characters. In SQL-mode, it is exactly every 4096 (a suspicious number indeed).
Here is some sample output:
brent@battlecruiser:/$ for i in {1..4096}; do echo -n 0; done; echo;
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
In this case, it should print out a single line of 0s, but in fact has inserted a new line character after 904 characters.
Also an Example in SQL Mode using MySQL:
mysql> show variables like '%n%';
+-----------------------------------------+----------------------------------+
| Variable_name | Value |
+-----------------------------------------+----------------------------------+
| auto_increment_increment | 1 |
| auto_increment_offset | 1 |
| binlog_cache_size | 32768 |
| binlog_format | STATEMENT |
| bulk_insert_buffer_size | 8388608 |
| character_set_client | utf8 |
| character_set_connection | utf8 |
| collation_connection | utf8_general_ci |
| collation_database | latin1_swedish_ci |
| collation_server | latin1_swedish_ci |
| completion_type | 0 |
| concurrent_insert | 1 |
| connect_timeout | 10 |
| delayed_insert_limit | 100 |
| delayed_insert_timeout | 300 |
| div_precision_increment | 4 |
| engine_condition_pushdown | ON |
| error_count | 0 |
| event_scheduler | OFF |
| foreign_key_checks | ON |
| ft_boolean_syntax | + -><()~*:""&| |
| ft_max_word_len | 84 |
| ft_min_word_len | 4 |
| ft_query_expansion_limit | 20 |
| general_log | OFF |
| general_log_file | /var/lib/mysql/battlecruiser.log |
| group_concat_max_len | 1024 |
| have_community_features | YES |
| have_dynamic_loading | YES |
| have_innodb | YES |
| have_ndbcluster | NO |
| have_openssl | DISABLED |
| have_partitioning | YES |
| have_symlink | YES |
| hostname | battlecruiser |
| identity | 0 |
| ignore_builtin_innodb | OFF |
| init_connect | |
| init_file | |
| init_slave | |
| innodb_adaptive_hash_index | ON |
| innodb_additional_mem_pool_size | 1048576 |
| innodb_autoextend_increment | 8 |
| innodb_autoinc_lock_mode | 1 |
| innodb_buffer_pool_size | 8388608 |
| innodb_checksums | ON |
| innodb_commit_concurrency | 0 |
| innodb_concurrency_tickets | 500 |
| innodb_data_file_path | ibdata1:10M:autoextend
|
| innodb_data_home_dir | |
| innodb_doublewrite | ON |
| innodb_fast_shutdown | 1 |
| innodb_file_io_threads | 4 |
| innodb_file_per_table | OFF |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_flush_method | |
| innodb_force_recovery | 0 |
| innodb_lock_wait_timeout | 50 |
| innodb_locks_unsafe_for_binlog | OFF |
| innodb_log_buffer_size | 1048576 |
| innodb_log_file_size | 5242880 |
| innodb_log_files_in_group | 2 |
| innodb_log_group_home_dir | ./ |
| innodb_max_dirty_pages_pct | 90 |
| innodb_max_purge_lag | 0 |
| innodb_mirrored_log_groups | 1 |
| innodb_open_files | 300 |
| innodb_rollback_on_timeout | OFF |
| innodb_stats_on_metadata | ON |
| innodb_support_xa | ON |
| innodb_sync_spin_loops | 20 |
| innodb_table_locks | ON |
| innodb_thread_concurrency | 8 |
| innodb_thread_sleep_delay | 10000 |
| innodb_use_legacy_cardinality_algorithm | ON |
| insert_id | 0 |
| interactive_timeout | 28800 |
| join_buffer_size | 131072 |
| keep_files_on_create | OFF |
| key_cache_division_limit | 100 |
| language | /usr/share/mysql/english/ |
| last_insert_id | 0 |
| lc_time_names | en_US |
| license | GPL |
| local_infile | ON |
| locked_in_memory | OFF |
| log_bin | OFF |
| log_bin_trust_function_creators | OFF |
| log_bin_trust_routine_creators | OFF |
| log_queries_not_using_indexes | OFF |
| log_warnings | 1 |
| long_query_time | 10.000000 |
| lower_case_table_names | 0 |
| max_binlog_cache_size | 4294963200 |
| max_binlog_size | 104857600 |
| max_connect_errors | 10 |
| max_connections | 151 |
| max_error_count | 64 |
| max_insert_delayed_threads | 20 |
| max_join_size | 18446744073709551615 |
| max_length_for_sort_data | 1024
|
| max_prepared_stmt_count | 16382 |
| max_sort_length | 1024 |
| max_sp_recursion_depth | 0 |
| max_user_connections | 0 |
| max_write_lock_count | 4294967295 |
| min_examined_row_limit | 0 |
| multi_range_count | 256 |
| myisam_data_pointer_size | 6 |
| myisam_recover_options | BACKUP |
| net_buffer_length | 16384 |
| net_read_timeout | 30 |
| net_retry_count | 10 |
| net_write_timeout | 60 |
| new | OFF |
| open_files_limit | 1024 |
| optimizer_prune_level | 1 |
| plugin_dir | /usr/lib/mysql/plugin |
| profiling | OFF |
| profiling_history_size | 15 |
| protocol_version | 10 |
| query_cache_min_res_unit | 4096 |
| query_cache_wlock_invalidate | OFF |
| rand_seed1 | |
| rand_seed2 | |
| range_alloc_block_size | 4096 |
| read_only | OFF |
| read_rnd_buffer_size | 262144 |
| relay_log_index | |
| relay_log_info_file | relay-log.info |
| rpl_recovery_rank | 0 |
| skip_external_locking | ON |
| skip_networking | OFF |
| slave_net_timeout | 3600 |
| slave_transaction_retries | 10 |
| slow_launch_time | 2 |
| sql_auto_is_null | ON |
| sql_log_bin | ON |
| sql_max_join_size | 18446744073709551615 |
| sql_notes | ON |
| sql_slave_skip_counter | |
| sql_warnings | OFF |
| storage_engine | MyISAM |
| sync_binlog | 0 |
| sync_frm | ON |
| system_time_zone | EDT |
| table_definition_cache | 256 |
| table_open_cache | 64 |
| thread_handling | one-thread-per-connection |
| time_zone | SYSTEM |
| transaction_alloc_block_size | 8192 |
| transaction_prealloc_size | 4096 |
| tx_isolation
| REPEATABLE-READ |
| unique_checks | ON |
| version | 5.1.41-3ubuntu12.10 |
| version_comment | (Ubuntu) |
| version_compile_machine | i486 |
| version_compile_os | debian-linux-gnu |
| warning_count | 0 |
+-----------------------------------------+----------------------------------+
159 rows in set (0.00 sec)
Here the output is always interrupted by a newline at exact intervals of 4096 characters.
In addition to possible solutions, any new ways to find more information about what is happening would be appreciated.
I have found the solution to this problem. I had put in my configuration file the following code sourced from http://www.emacswiki.org/emacs/SqlMode
After removing the code (which because it sets the
comint-preoutput-filter-functions, affectsshell-modeas well), I no longer experience these issues.My proposed replacement for this code to get the behavior I want (works for me so far):
Essentially, I am adding the hook right before my sql-send-region-better code starts sending output, then inside the hook I am removing the hook again, guaranteeing that it only inserts the one new line that I want.