René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Tasks]: Basics of coding on RISC OS, level 3","articleBody":"### Contact Details (optional)\n\n_No response_\n\n### Background\n\nLevel 1: Getting the source (from Git)\r\nLevel 2: Making system calls to flash an LED\r\n\r\nThis task outlines level 3 of the course, a little bit harder, building on levels 1 and 2. Based on feedback given at the meeting where level 2 was shown and comments on the videos this next instalment should:\r\n\r\n- Continue to be single tasking/command line based\r\n- Comprise more than 1 source file (as a means to introduce using a makefile, or needing to link 2 or more objects together, or the equivalent in the respective language, eg. `LIBRARY` in BASIC)\r\n- Comment on where to find background material in the PRMs or StrongHelp manuals (rather than just pulling magic numbers out of the air)\r\n- Handle the error return from a `_swix` call (or equivalent, eg. `SYS` in BASIC)\r\n- Use file I/O (contrasting the language built ins like `fopen()` or `OPENIN` with SWI OS_File and OS_Find)\r\n\r\nA tutorial example which takes a sprite or JPEG, queries its dimensions, and prints them to the console. With a suitable framework this could be extended for other types by the avid reader like PNG or GIF, and take the general form\r\n\r\n`*ImageInfo \u003cimagefile\u003e`\r\n\r\nAt level 2 we presented (in order of [most number of views](https://www.youtube.com/playlist?list=PLEnraaJ9VQfXFQCVSmUgabVmdvqmLDgZZ) first)\r\n\r\n1. Assembler (gas syntax, ObjAsm optional)\r\n2. C (with the DDE, gcc optional)\r\n3. C++ (in CFront, g++ optional)\r\n4. Python\r\n5. BBC BASIC\r\n6. Lua\r\n\r\nDon't be limited by these 6 though! All languages for which there is a RISC OS variant are up for grabs if volunteers have a particular area of interest they'd like to produce.\n\n### Definition of Done\n\nPaolo has kindly offered to 'top \u0026 tail' any videos submitted. \r\n\r\nThe meeting to review this topic is 03-Jun-2023, so ideally material needs to be complete by 27-May-2023 to give time for editing.\r\n\r\nThis task would be complete once the new level 3 videos are edited and available on youtube for developers.\n\n### Code of Conduct\n\n- [X] I agree to follow this project's Code of Conduct","author":{"url":"https://github.com/rps102","@type":"Person","name":"rps102"},"datePublished":"2023-05-24T06:30:28.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/37/CodingOnRISC-OS/issues/37"}