Progression Handler: Progress Reported as the Size of a File on the File System

handler_filesize(
file = "default.progress",
intrusiveness = getOption("progressr.intrusiveness.file", 5),
target = "file",
...
)

## Arguments

file

(character) A filename.

intrusiveness

(numeric) A non-negative scalar on how intrusive (disruptive) the reporter to the user.

target

(character vector) Specifies where progression updates are rendered.

...

Additional arguments passed to make_progression_handler().

## Details

This progression handler reports progress by updating the size of a file on the file system. This provides a convenient way for an R script running in batch mode to report on the progress such that the user can peek at the file size (by default in 0-100 bytes) to assess the amount of the progress made, e.g. ls -l -- *.progress. If the *.progress file is accessible via for instance SSH, SFTP, FTPS, HTTPS, etc., then progress can be assessed from a remote location.

## Examples

if (FALSE) {
handlers(handler_filesize(file = "myscript.progress"))
with_progress(y <- slow_sum(1:100))
print(y)
}