GitHub - r-lib/asciicast: Turn R scripts into terminal screencasts (original) (raw)
asciicast
Turn R scripts into terminal screencasts
asciicast takes an R script and turns it into anasciinema cast. It can simulate typing, and records all terminal output in real time as it happens.
Features
- Input is an R script, output is a v2 asciicast recording.
- Record all terminal output in real time, as it happens.
- Simulate typing in the commands, with a configurable, randomized speed.
- Alternatively, whole comment blocks or expressions can just appear on the screen.
- Convert casts to SVG images usingsvg-term. The package comes with its own svg-term bundle, no external dependencies are needed.
- Render a single frame of a cast as an SVG image.
- Configurable delay at the beginning, at the end and between paragraphs.
- HTML widget, to be used in Rmarkdown documents, e.g. in vignettes.
- Read casts from asciinema JSON files (version 2), or fromhttps://asciinema.org directly.
- Special knitr engine to create R markdown files with ascii casts. See the
asciicast-demovignette. - Create ascii casts in GitHub READMEs via animated SVG files. See an example in
inst/examplesor theREADME.Rmdsource of the README file you are reading.
Limitations
- asciicast works best in an UTF-8 locale. It also works well if all output is ASCII, but non-ASCII output might cause problems (#36).
Installation
You can install the released version of asciicast fromCRAN:
install.packages("asciicast")
Examples
See the inst/examplesdirectoryfor these examples.
Hello world
The input script:
The result:
Asciicast demo in asciicast
Input script that uses asciicast itself:
#' Title: asciicast example recorded in asciicast #' Empty_wait: 3 #' End_wait: 20
An example for using asciicast, recorded in asciicast itself! #!
First, save the R code you want to run, in a script file. #!
The file can contain any code, including interactive code, #!
as long as it is a syntactically valid R file. #!
Second, perform the recording with the record() function. #!
We are recording an example file now, that comes with the package. #!
src <- system.file("examples", "hello.R", package = "asciicast") cast <- asciicast::record(src)
cast is an asciicast object, which has some metadata and the #!
recording itself: #!
cast
You can write cast to a JSON file that can be played by any #!
asciinema player. Or you can write it to an SVG file that can #!
be embedded into a web page, or a GitHub README. #!
svg <- tempfile(fileext = ".svg") asciicast::write_svg(cast, svg, window = TRUE)
Errors are recorded
Input script with errors:
#' End_wait: 20
Demonstrate that errors are handled well
Base R error
library("not-this-really") traceback()
callr errors are saved to .Last.error, including a stack trace
library(cli) callr::r(function() library("another-failure")) .Last.error
Related tools
- asciinema: https://asciinema.org/
- The original terminal session recorder:https://github.com/asciinema/asciinema
- svg-term: https://github.com/marionebl/svg-term,https://github.com/marionebl/svg-term-cli
License
MIT @ RStudio