Why org mode is good? Tables fc position ease box interval due front 2.20 3 6.00 2021-09-06T07:56:14Z ref note: ¦ is broken pipe used as a replacement of | to escape it.
create column ¦¦ create table with predefined columns `C-c ¦` create new row <TAB> from last row visit each column S-<TAB> or <TAB> , or any seperated region into table select region and C-c ¦ force separator:, TAB and 3 spaces C-u or C-u C-u or C-u 3 C-c ¦ change column order M-<right> or M-<left> change row order M-<up> or M-<down> inserting/deleting row/column S-M-<down> or <right> add more lines to the table C-c ~ edit table C-c ' Useful shortcuts C-c C-x p: set properties C-c -: Insert separator line in table or modify bullet status of line....
sudo vs su ref
su switch user by default to root user opens a shell to run command prompts for root password su run program as root and asks for root password
su username “su -” vs “sudo -i” both does same
“su” vs “su -” “su” does not change
current working dir aliases env “su -”
change current working dir sets env as if logged in as root sudo runs command as root in the same shell....
Summary ref Shaka Player is an open-source JavaScript library for adaptive media. It plays adaptive media formats (such as DASH and HLS [HLS Format]) in a browser, without using plugins or Flash. Instead, Shaka Player uses the open web standards MediaSource Extensions and Encrypted Media Extensions.
Where I used it? In Tadafuq project, mux.js was required to play the video. from this discussion mux.js can be used in React or Vue by doing in the component before using Shaka Player...
Summary HTTP Live Streaming ref HLS format is an adaptive bitrate live streaming video protocol. Originally developed by Apple for use on iOS, Mac OS, and Apple TV devices, HLS streaming has become the most widely used live video protocol or web video.
Pros Excellent quality Supported on all devices Cost efficient Privacy and Security Cons Latency Internet speed Therefore, it usually adds a delay of 20-60 seconds to your stream...
Summary A complete, cross-platform solution to record, convert and stream audio and video. https://ffmpeg.org/
Examples Encoding or converting will be as easy as ffmpeg -i input.mp4 output.avi Video streams can be converted and broken into appropriate segments by FFmpeg with a command such as ffmpeg -i inputFile.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 outputFile.m3u8 Where I used this? In tfarraj project, this library was used in the upload-encoder project, which uses fluent-ffmpeg npm module or library to make complex command-line into easy and fluent....
Summary Application level protocol
HTTP response status codes ref Informational responses (100–199) Successful responses (200–299) Redirects (300–399) Client errors (400–499) Server errors (500–599)
ref
5xx 503 ref A 503 Service Unavailable Error is an HTTP response status code indicating that a server is temporarily unable to handle the request. This may be due to the server being overloaded or down for maintenance.
4xx 401 (Unauthorized) When the client provides no credentials or invalid credentials....
Summary Upgrade on Debian Versions Supported versions on apache: https://packages.debian.org/search?searchon=names&keywords=apache2 apps-4 current version on Debian 10 Server version: Apache/2.4.38 (Debian)
on Debian 10 with backports is 2.4.52-1 https://packages.debian.org/buster-backports/apache2
on Debian 11 is 2.4.53-1 https://packages.debian.org/bullseye/apache2 Issues Linux OS and packages are not patched/updated regularly, manage server broken Solutions Apache HTTP Server mod_proxy SSRF: update apache to latest supported https://www....