https://github.com/jeroenjanssens/rexpect

Automate Interactive Applications in R
https://github.com/jeroenjanssens/rexpect

automation expect rstats

Last synced: 14 days ago
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Automate Interactive Applications in R

• Host: GitHub
• URL: https://github.com/jeroenjanssens/rexpect
• Owner: jeroenjanssens
• License: other
• Created: 2019-12-27T12:26:22.000Z (almost 5 years ago)
• Default Branch: main
• Last Pushed: 2024-04-26T12:15:40.000Z (7 months ago)
• Last Synced: 2024-10-13T02:14:26.063Z (29 days ago)
• Topics: automation, expect, rstats
• Language: R
• Homepage: https://jeroenjanssens.github.io/rexpect/
• Size: 4.04 MB
• Stars: 11
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

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README

        
---

output:

  github_document:

    html_preview: true

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "man/figures/README-",

  out.width = "100%"

)

```

# rexpect 

[![Lifecycle: stable](https://img.shields.io/badge/lifecycle-stable-green.svg)](https://www.tidyverse.org/lifecycle/#stable)

`rexpect` is an R package that allows you to automate interactions with programs that

expose a text terminal interface. The API is inspired by the original Expect tool by Don Libes.

## Installation

You can install the development version from [GitHub](https://github.com/) with:

```{r, eval = FALSE}

# install.packages("remotes")

remotes::install_github("jeroenjanssens/rexpect")

```

## Example

Let's say we have a Python script that repeatedly asks for a number.

When the user enters `sum`, the script prints the sum of all the numbers.

The script exits when the user presses `CTRL-C`. 

Here's the contents of _bin/sum.py_:

```{verbatim, file = "bin/sum.py", lang = "python"}

```

We can use `rexpect` to run this script and interact with it.

Let's enter the numbers 7, 13, and 22 and see what the sum is:

```{r}

library(rexpect)

session <- spawn("bin/sum.py", prompt = "^(.*):$")

send_lines(session, c("7", "13", "22", "sum"), wait = TRUE)

```

Under the hood, `rexpect` starts a tmux session using [tmuxr](https://jeroenjanssens.github.io/tmuxr):

```{r}

session

```

We can capture the output and extract the sum:

```{r}

print(output <- read_all(session))

as.numeric(gsub("[^0-9.]", "", output[length(output) - 1]))

```

We've accomplished our goal, so let's exit:

```{r}

send_lines(session, "exit")

read_all(session)

```

Oh that's right, we need to press `CTRL-C` to exit the script:

```{r}

send_control_c(session)

```

This was a rather simple example to demonstrate some of the capabilities of `rexpect`.

The session could have taken place inside a Docker container or over SSH. 

We could also have recorded the session using [asciinema](https://asciinema.org/).

Have a look at [the function reference](https://jeroenjanssens.github.io/rexpect/reference/) to learn more about what `rexpect` has to offer.

## License

The `rexpect` package is licensed under the MIT License.