nextbus

Authors:

• Nathan Karasch ([email protected])
  • Main author. Made this program as a Com S 327 assignment.
• Jeremy Sheaffer ([email protected])
  • Extended his command-line argument parser from the Com S 327 assignment.
• Mark Lakata (http://stackoverflow.com/users/364818/mark-lakata)
  • Used his curl/curl.h wrapper solution in the CURLplusplus class found on this StackOverflow post

Compiling:

$ make

Description:

This program interfaces with the NextBus API to display NextBus information for CyRide in Ames, IA. It can return bus route information in a variety of formats, based on user input of route, stop, etc. The user is also able to configure the program so that they can quickly find out the time of the next bus heading home or the time of the next bus heading to school/work without having to manually type all the optional parameters. The program is meant to be extensible to other bus lines (not just CyRide), but the target for this assignment is CyRide, so any special implementation needed for other bus lines was not tested.

The program curls the NextBus information from an http request, which comes back in XML form. The program parses the XML and pulls out data that it will show the user. XML data that can be reasonably cached and referenced later is saved in the directory $HOME/.nextbus/. The config.nextbus file is also created and saved there.

The configuration file holds user-specific information, such as saved routes/stops and current agency (ex: CyRide). It also holds integers that represent epoch time for last usage of nextbus and last download of the route configuration for the given agency. These are used by the program to determine if it should use the cached information or download new info from the NextBus API. Using the cached data is obviously faster, but you also don't want to use data that's too old. The user can force using online data with the -o|--online flag or force using cached data with the -c|--cached flag. Forcing online can be useful if you know the information is outdated. Forcing cached can be useful if you don't have internet and want to look at the cached bus schedule information, which is probably still accurate.

The most practical usage of the program is the saved route/stop feature. When you're working late into the night on your Com S 327 assignment and you're ready to go home, just type nextbus home and get bus arrival estimations without ever having to leave the terminal! Computer Science and Software Engineering majors at ISU, you're welcome. ;-)

Getting Started:

First, you need to run the program once with any parameters, which will force the program to create a new config file. If you're not a Cyclone, you'll need to run nextbus -a to list the different NextBus agencies, and then set your desired agency with nextbus -A <agency>. Finally, set variables for home, work, etc. using nextbus -S <name> <route> <stop>.

Usage:

nextbus [
          [ <save-name-1> <save-name-2> ...           ]
          [ -a | --agencies                           ]
          [ -A | --AgencyStore  <agency>              ]
          [ -c | --cached                             ]
          [ -h | --help                               ]
          [ -m | --minutes      <save-name>           ]
          [ -o | --online                             ]
          [ -p | --predictstop  <stop>                ]
          [ -P | --PredictRoute <route> <stop>        ]
          [ -r | --routes                             ]
          [ -S | --Save         <name> <route> <stop> ]
          [ -s | --schedule     <route>               ]
          [ -l | --liststops    <route>               ]
        ]

Flags/Parameters:

<save-name-1> <save-name-2> ...

Type any of your saved route/stop variables to get predictions for that route/stop.

Example: nextbus work1 work2

-a | --agencies

Lists all the agencies serviced by NextBus.

-A | --AgencyStore <agency>

Stores the given agency as your default agency for getting schedules and predictions.

-c | --cached

Forces the program to used cached schedule and route information. Doesn't work with predictions, since they always need to be up-to-date information. This can be useful for getting schedule/route information when offline.

-h | --help

Displays information from the README about how to use the program.

-m | --minutes <save-name>

Gets the predictions for a saved route/stop and displays only the minutes until the soonest bus arrives/departs.

-o | --online

Forces the program to pull data from online rather than using cached information. Otherwise the program will use cached information for schedules and route info if the information isn't too old.

-p | --predictstop <stop>

Shows predictions for all arriving/departing routes at a given stop number.

Example: nextbus -p 1166

-P | --PredictRoute <route> <stop>

Shows predictions for the given route at the given stop.

Example: nextbus -P 2E 1123

-r | --routes

Lists all routes for the current agency.

-S | --Save <name> <route> <stop>

Saves the given route and stop to a variable name that can be used with nextbus <save-name-1> <save-name-2> ...

Example: nextbus -S home 1W 1166

-s | --schedule <route>

Displays the bus schedule for the given route.

Example: nextbus -s 2E

-l | --liststops <route>

Lists all stops for the given route.

Example: nextbus -l 2E