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tags: []
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# Eòlas

Hi, I'm [Thomas](https://systemsobscure.blog/). This is the frontend of
[Eòlas](https://github.com/thomasabishop/eolas), my personal knowledge base. It
is a [Zettelkasten](https://en.wikipedia.org/wiki/Zettelkasten) work in progess
comprising notes from my self-directed study of software engineering and
computer science.
 
**Build ID:** 57f4d44e-6e5d-4bdf-a12c-b7dac10ca90d

**Published:** Mon 21 Oct 2024 13:04:00

### Recent edits 

- [[Compile_Python_app_to_single_executable]] 
- [[VirtualMemory]] 
- [[Zero_property_of_multiplication]] 
- [[Working_with_CSVs_in_Python]] 
- [[Variables_and_data_types_in_Bash]] 
- [[Validity_and_entailment]] 
- [[Utilities_operators_flags]] 
- [[Turing_machines]] 


### All notes (462) 

- [[API_Gateway]] 
- [[AWS_CLI]] 
- [[AWS_SAM_and_Docker]] 
- [[AWS_architecture_hierarchy]] 
- [[Accessing_metadata_about_SQL_database]] 
- [[Accessing_secrets_from_a_Lambda]] 
- [[Add_Subtract_Fractions]] 
- [[Adding_documents_to_a_Mongo_collection]] 
- [[Additive_identity]] 
- [[Additive_inverse_property]] 
- [[Aggregate_functions_in_SQL]] 
- [[Algebra_key_terms]] 
- [[Algorithmic_complexity]] 
- [[Analogue_and_digital]] 
- [[Any]] 
- [[Apollo_Client]] 
- [[Apollo_Server]] 
- [[Application_Layer_of_Internet_Protocol]] 
- [[Application_state_management_with_React_hooks]] 
- [[Application_structure]] 
- [[Arithmetic_Logic_Unit]] 
- [[Arrays]] 
- [[Assembly]] 
- [[Associativity]] 
- [[Atomic_and_molecular_propositions]] 
- [[Awk]] 
- [[Axioms_of_set_theory]] 
- [[Basic_model_of_the_operating_system]] 
- [[Basic_prop_passing_in_React]] 
- [[Basic_properties_of_sets]] 
- [[Basics_of_web_components]] 
- [[Biconditional_Elimination]] 
- [[Biconditional_Introduction]] 
- [[Binary_addition]] 
- [[Binary_arithmetic]] 
- [[Binary_colour_encoding]] 
- [[Binary_encoding]] 
- [[Binary_encoding_of_text]] 
- [[Binary_number_system]] 
- [[Binary_units_of_measurement]] 
- [[Bitwise_operators]] 
- [[Bluetooth]] 
- [[Boolean_algebra]] 
- [[Boolean_function_synthesis]] 
- [[Boolean_functions]] 
- [[Boot_process]] 
- [[Breadboards]] 
- [[Built_in_React_hooks]] 
- [[Bus]] 
- [[CPU_architecture]] 
- [[Call_stack]] 
- [[Capturing_user_input_in_Bash]] 
- [[Case_statements_in_Bash]] 
- [[Cells_and_batteries]] 
- [[Cherry_picking]] 
- [[Child_to_parent_data_flow_in_React]] 
- [[Chipset_and_controllers]] 
- [[Class_inheritance_in_Python]] 
- [[Classes]] 
- [[Classes_in_Python]] 
- [[Clock_signals]] 
- [[CloudWatch]] 
- [[Command_pattern]] 
- [[Commutativity]] 
- [[Comparing_React_classes_to_hooks]] 
- [[Compile_Python_app_to_single_executable]] 
- [[Compile_from_source]] 
- [[Complete_Mongo_example]] 
- [[Components_props_classes]] 
- [[Components_props_hooks_in_React]] 
- [[Concise_subfield_mapping_JS]] 
- [[Conditional_Elimination]] 
- [[Conditional_Introduction]] 
- [[Conditional_statements_in_Python]] 
- [[Conditionals_in_Bash]] 
- [[Conjunction_Elimination]] 
- [[Conjunction_Introduction]] 
- [[Connect_to_Mongo_database]] 
- [[Connecting_a_frontend_to_a_Docker_backend]] 
- [[Containerization]] 
- [[Controlled_components_in_React]] 
- [[Corresponding_material_and_biconditional]] 
- [[Coulombs_Laws]] 
- [[Create_Mongo_database]] 
- [[Create_an_SQL_table]] 
- [[Create_timed_systemd_job]] 
- [[Creating_a_Docker_image]] 
- [[Creating_a_Linux_partition_table]] 
- [[Creating_a_Mongo_schema_and_model]] 
- [[Creating_a_RESTful_API_GET]] 
- [[Creating_a_RESTful_API_Integrating_the_Database]] 
- [[Creating_a_RESTful_API_Introduction]] 
- [[Creating_a_RESTful_API_POST]] 
- [[Creating_a_RESTful_API_PUT]] 
- [[Creating_memory_with_NAND]] 
- [[Cron]] 
- [[Current]] 
- [[Custom_React_hook_examples]] 
- [[Custom_types_in_TypeScript]] 
- [[DRAM_and_SRAM_memory]] 
- [[Daemons]] 
- [[Data_types_in_Bash]] 
- [[Data_types_in_MySQL]] 
- [[Database_indices]] 
- [[Database_options_on_AWS]] 
- [[Dates_in_Python]] 
- [[DeMorgan's_Laws]] 
- [[Defining_a_computer]] 
- [[Delay_line_memory]] 
- [[Delete_a_branch]] 
- [[Delete_records_in_an_SQL_table]] 
- [[Deleting_Mongo_documents]] 
- [[Dependency_injection]] 
- [[Devices]] 
- [[Dictionaries_in_Python]] 
- [[Difference_between_remote_origin_and_head]] 
- [[Disjunction_Elimination]] 
- [[Disjunction_Introduction]] 
- [[Disk_info]] 
- [[Distributivity]] 
- [[Dividing_fractions]] 
- [[Docker_CLI]] 
- [[Docker_Compose]] 
- [[Docker_architecture]] 
- [[Docker_compose_and_Dockerfile_difference]] 
- [[Docker_containers]] 
- [[Docker_general_overview]] 
- [[Docker_images]] 
- [[Docker_storage]] 
- [[DynamoDB_CLI_commands]] 
- [[DynamoDB_SDK_commands]] 
- [[DynamoDB_data_structure]] 
- [[Effective_logging_in_Git]] 
- [[Elastic_Compute_Cloud]] 
- [[Electromagnetism]] 
- [[Electrons]] 
- [[Enums]] 
- [[Environmental_and_shell_variables]] 
- [[Equivalent_equations]] 
- [[Equivalent_fractions]] 
- [[Error_handling_in_Python]] 
- [[Event_loop]] 
- [[Example_scenario_internet_data_transfer]] 
- [[Expansions_and_substitutions]] 
- [[Exponents]] 
- [[Expressing_whole_numbers_as_fractions]] 
- [[Factors_and_divisors]] 
- [[Factory_pattern]] 
- [[Fetch_decode_execute]] 
- [[Fetch_from_Secrets_Manager]] 
- [[File_descriptors]] 
- [[File_permissions_and_execution_in_Bash]] 
- [[Filesystems]] 
- [[Find_Bash_command]] 
- [[Flip_flops]] 
- [[Foreign_keys_in_SQL]] 
- [[Formal_conventions]] 
- [[Formal_proofs_in_propositional_logic]] 
- [[Format_specifiers_in_C]] 
- [[Formatting_output_text_in_Bash]] 
- [[Forms_in_React]] 
- [[Four_bit_adder]] 
- [[Frequency_counters]] 
- [[Full_Node_API_example]] 
- [[Function_overloads]] 
- [[Functions]] 
- [[Functions_in_Bash]] 
- [[Functions_in_Python]] 
- [[Fundamental_Theorem_of_Arithmetic]] 
- [[Further_examples_of_TS_generics]] 
- [[GPU_versus_CPU]] 
- [[Generics_in_TypeScript]] 
- [[Git_bisect]] 
- [[Git_rebasing]] 
- [[Global_object_in_NodeJS]] 
- [[Grep]] 
- [[Ground]] 
- [[Guide_to_YAML]] 
- [[HTTP_request_types]] 
- [[Half_adder_and_full_adder]] 
- [[Handle_multiple_endpoints_single_lambda]] 
- [[Handling_negative_fractions]] 
- [[Hardware_Description_Language]] 
- [[Hardware_abstraction_and_modularity]] 
- [[Hardware_simulation]] 
- [[Headless_Raspi_network_setup]] 
- [[Heap_memory]] 
- [[Hexadecimal_number_system]] 
- [[IO_in_Python]] 
- [[IP_addresses]] 
- [[Identify_merged_branches]] 
- [[Importing_MongoDB_data]] 
- [[Increasing_fractions_to_their_highest_terms]] 
- [[Insert_data_into_SQL_table]] 
- [[Instruction_set_architectures]] 
- [[Integers]] 
- [[Integrated_circuits]] 
- [[Interactive_staging]] 
- [[Internet_Layer_of_Internet_Protocol]] 
- [[Internet_fundamentals]] 
- [[Intersection_types_in_TypeScript]] 
- [[Intro_to_the_Unix_shell]] 
- [[Inversion_of_operators]] 
- [[Invoking_the_shell_in_Python]] 
- [[Iterating_in_React]] 
- [[Iterating_through_complex_data_structures_in_Python]] 
- [[Joins_in_SQL]] 
- [[Journey_of_GraphQL_query]] 
- [[Key_characteristics_of_GraphQL]] 
- [[Killing_processes]] 
- [[LEDs]] 
- [[Lambda_directory_structure]] 
- [[Lambda_handler_function]] 
- [[Lambda_programming_model]] 
- [[Lambda_triggers]] 
- [[Lambdas_in_Python]] 
- [[Latches]] 
- [[Law_of_Non_Contradiction]] 
- [[Law_of_the_Excluded_Middle]] 
- [[Lifecycle_methods]] 
- [[Link_Layer_of_Internet_Protocol]] 
- [[Linux_disk_partitions]] 
- [[List_comprehension_in_Python]] 
- [[Listing_and_navigating_directories_in_the_Shell]] 
- [[Lists_and_arrays_in_Bash]] 
- [[Lists_in_Python]] 
- [[Local_AWS_development_with_SAM]] 
- [[Logarithms]] 
- [[Logic_gates]] 
- [[Logical_consistency]] 
- [[Logical_equivalence]] 
- [[Logical_indeterminacy]] 
- [[Logical_possibility_and_necessity]] 
- [[Logical_truth_and_falsity]] 
- [[Loops_in_Python]] 
- [[Loops_in_bash]] 
- [[MAC_addresses]] 
- [[Machine_code]] 
- [[Magnetic_core_memory]] 
- [[Magnetic_drum_memory]] 
- [[Magnetic_tape]] 
- [[Mainframe_computers]] 
- [[Managing_environments_in_NodeJS]] 
- [[Map_and_filter_in_Python]] 
- [[Map_and_filter_to_reduce_in_JS]] 
- [[Mapped_types_in_TS]] 
- [[Maps_and_sets_in_JS]] 
- [[Match_statements_in_Python]] 
- [[Matter_and_atoms]] 
- [[Memoization_in_React]] 
- [[Memory_Management_Unit]] 
- [[Memory_addresses]] 
- [[Memory_leaks]] 
- [[Memory_versus_processor]] 
- [[Messaging_services]] 
- [[Middleware_in_NodeJS]] 
- [[Mixed_and_improper_fractions]] 
- [[Modelling_relationships_in_MongoDB]] 
- [[Module_pattern]] 
- [[Module_wrapping_at_runtime]] 
- [[Modules_in_NodeJS]] 
- [[MongoDB_Introduction]] 
- [[Monitoring_processes_and_resources]] 
- [[Morgan]] 
- [[Motherboard]] 
- [[Multiple_pointers]] 
- [[Multiplexers_and_demultiplexers]] 
- [[Multiplicative_identity]] 
- [[Multiplicative_property_of_negative_one]] 
- [[Multiplying_fractions]] 
- [[Mutations_with_Apollo_Client]] 
- [[Naming_conventions]] 
- [[Natural_numbers]] 
- [[Negation_Elimination]] 
- [[Negation_Introduction]] 
- [[Negative_exponents]] 
- [[Network_card]] 
- [[Network_debugging]] 
- [[Network_fundamentals]] 
- [[Network_hosts]] 
- [[Network_protocols]] 
- [[Network_requests_in_Python]] 
- [[Network_scanning]] 
- [[NodeJS_scripts]] 
- [[Node_and_MySQL_db]] 
- [[Nodemon]] 
- [[Non_null_assertion_in_TypeScript]] 
- [[None_in_Python]] 
- [[Numbers_in_Python]] 
- [[Object_language_and_meta_language]] 
- [[Observer_pattern]] 
- [[Ohms_Law]] 
- [[OpenSearch]] 
- [[Operating_system_API]] 
- [[Order_of_operations]] 
- [[Package_management_in_NodeJS]] 
- [[Packet_switching_British_precursors]] 
- [[Pacman]] 
- [[Passing_arguments_and_options_to_Bash_scripts]] 
- [[Passing_arguments_to_Python_scripts]] 
- [[Peer_to_peer_network]] 
- [[Ports_in_NodeJS]] 
- [[Practical_walkthrough_Lambda_creation_within_AWS]] 
- [[Prefixes_for_units_of_electrical_measurement]] 
- [[Prime_factorization]] 
- [[Primes_and_composites]] 
- [[Primitive_types]] 
- [[Printing_values_in_C]] 
- [[Process_module_in_NodeJS]] 
- [[Processes]] 
- [[Prop_types_in_React]] 
- [[Proper_shebang_syntax]] 
- [[Props_in_React]] 
- [[Prototypical_inheritance]] 
- [[Push_buttons]] 
- [[Python_application_structure]] 
- [[Python_data_types]] 
- [[Python_execution]] 
- [[Python_interpreter]] 
- [[Python_modules_and_imports]] 
- [[Python_package_management]] 
- [[Querying_a_Mongo_collection]] 
- [[Queue]] 
- [[Quote_marks_in_Bash]] 
- [[RESTful_APIs]] 
- [[ROM_versus_disk_loading]] 
- [[React_Components]] 
- [[React_errors]] 
- [[React_useContext]] 
- [[React_useEffect]] 
- [[React_useReducer]] 
- [[React_useState]] 
- [[Read_command__in_Bash]] 
- [[Reciprocals]] 
- [[Recursion]] 
- [[Redirect_to_dev_null]] 
- [[Redirection_in_Bash]] 
- [[Reducing_fractions]] 
- [[Register_and_cache_memory]] 
- [[Regular_expressions_in_SQL]] 
- [[Reiteration]] 
- [[Relation_between_kernel_and_CPU]] 
- [[Relational_database_architecture]] 
- [[Relays]] 
- [[Remote_tracking_branches]] 
- [[Rename_a_branch]] 
- [[Reset_to_remote_version]] 
- [[Resistance]] 
- [[Restructure_URLs_lambda]] 
- [[Retrieve_data_from_SQL_table]] 
- [[Role_of_memory_in_computation]] 
- [[Role_of_unique_key_in_relational_databases]] 
- [[Routing_on_link_click_in_React]] 
- [[Rules_for_operations_on_like_and_unlike_terms]] 
- [[S3]] 
- [[SAM]] 
- [[Save_readonly_Vim_file]] 
- [[Schema_Definition_Language_in_GraphQL]] 
- [[Secrets_or_env_vars_in_AWS]] 
- [[Semantic_versioning]] 
- [[Set_DNS_settings]] 
- [[Sets_in_Python]] 
- [[Setting_up_and_configuring_TypeScript]] 
- [[Shell_sessions]] 
- [[Signed_and_unsigned_numbers]] 
- [[Signed_magnitude_representation]] 
- [[Single_file_Python_scripts]] 
- [[Singleton_pattern]] 
- [[Sliding_window]] 
- [[Solving_equations]] 
- [[Sorting_lists_in_Python]] 
- [[Soundness]] 
- [[Split_into_array_in_Bash]] 
- [[Stack_memory]] 
- [[Stacks]] 
- [[Stale_branches_and_pruning]] 
- [[Step_functions_and_state_machines]] 
- [[Strategies_for_constructing_proofs]] 
- [[Streams_in_NodeJS]] 
- [[Strings_in_Bash]] 
- [[Strings_in_Python]] 
- [[Structuring_Express_applications]] 
- [[Substrings_in_Bash]] 
- [[Swap_space]] 
- [[Switch_between_Python_vers]] 
- [[Syllogism]] 
- [[Symlinks]] 
- [[Syntax_of_propositional_logic]] 
- [[Tags_in_Git]] 
- [[Test_values_in_Bash]] 
- [[Testing_Python_code]] 
- [[Testing_with_Jest]] 
- [[Text_manipulation_in_Bash]] 
- [[The_History_of_Computing_Swade]] 
- [[The_Little_Man_computer]] 
- [[The_PATH]] 
- [[The_Pragmatic_Programmer_1999]] 
- [[The_kernel]] 
- [[The_memory_hierarchy]] 
- [[Theorems_and_empty_sets]] 
- [[Threads]] 
- [[Three_bit_counter]] 
- [[Time_and_computers]] 
- [[Torrenting]] 
- [[Transistors]] 
- [[Transport_Layer_of_Internet_Protocol]] 
- [[Troubleshooting_MongoDB]] 
- [[Truth_functional_connectives]] 
- [[Truth_tables]] 
- [[Truth_trees]] 
- [[Tuples_in_Python]] 
- [[Turing_completeness]] 
- [[Turing_machines]] 
- [[Twos_complement]] 
- [[Type_guarding_and_narrowing_in_TS]] 
- [[Type_hinting]] 
- [[Union_types_in_TS]] 
- [[Unknown_type_in_TS]] 
- [[Untitled]] 
- [[Update_a_Mongo_document]] 
- [[Update_an_SQL_table]] 
- [[Update_existing_data_in_SQL_table]] 
- [[Useful_operators_in_SQL]] 
- [[User_Space]] 
- [[User_management_in_Linux]] 
- [[User_management_on_AWS]] 
- [[Using_GraphQL_with_Node]] 
- [[Using_arguments_with_Apollo_Client]] 
- [[Utilities_operators_flags]] 
- [[Validating_Mongoose_schemas]] 
- [[Validation_in_NodeJS]] 
- [[Validity_and_entailment]] 
- [[Variable_indirection_in_Bash]] 
- [[Variables_and_data_types_in_Bash]] 
- [[Variables_in_C]] 
- [[Viewing_remote_changes_without_merging]] 
- [[Views_in_relational_databases]] 
- [[VirtualMemory]] 
- [[Virtual_private_cloud]] 
- [[Voltage]] 
- [[Voltage_sources]] 
- [[What_are_disks]] 
- [[What_is_memory]] 
- [[Whole_numbers]] 
- [[Why_computers_use_binary]] 
- [[Wildcards_in_SQL]] 
- [[Williams_Tube_memory]] 
- [[Working_with_CSVs_in_Python]] 
- [[Working_with_JSON_in_Python]] 
- [[Working_with_numbers_in_Bash]] 
- [[Zero_property_of_multiplication]] 
- [[Zip_function_in_Python]] 
- [[fs]] 
- [[http_in_Node]] 
- [[journald]] 
- [[jq]] 
- [[ps]] 
- [[python_advent_learnings]] 
- [[systemd]] 
- [[systemd_status]] 
- [[v8]] 
