rayvn/asciinema

Asciinema cast recording and post-processing.

Functions

asciinemaRecord()

Record one or more commands with asciinema and post-process the cast in-place. Deletes any existing cast file, records each command separately with a simulated typing prelude, concatenates them into a single cast, and trims the terminal dimensions to fit the content.

The recording PTY is sized to the host terminal so interactive widgets render correctly. Falls back to 220x24 if the terminal size cannot be detected.

args


`castFile` (string)	Output path for the cast file.

options

–cmd CMD Command to record (repeatable; required; each recorded as a separate segment with its own typing prelude, concatenated in order). –pre CMD Shell command to run before recording (optional; runs in current shell). –post CMD Shell command to run after recording (optional; runs in current shell). –wpm N Typing speed in words per minute (default: 120). –prompt TEXT Shell prompt text (default: ‘[COMMAND]$ ‘). –no-trim Skip trimming terminal dimensions to content.

notes

Requires asciinema in PATH. The cast file is overwritten if it exists. –pre and –post run once, wrapping all –cmd recordings as a group.

typistAsciinemaEvents()

Output asciinema event lines simulating TEXT typed at WPM words per minute. Uses typistDelays for timing, then formats each character as a JSON event. Includes a final Enter key event.

args


`wpm` (int)	Typing speed in words per minute.
`text` (string)	The text to simulate typing.

output

Asciinema event JSON lines, one per character, followed by an Enter event.

example

typistAsciinemaEvents 120 "rayvn test" >> typing.cast

asciinemaTypingFile()

Generate a typing events file for use as a cast prelude. Writes a prompt event followed by per-character events for COMMAND.

args


`wpm` (int)	Typing speed in words per minute.
`prompt` (string)	Shell prompt text (e.g. ‘[rayvn]$ ‘).
`command` (string)	Command text to simulate typing.
`outputFile` (string)	Path to write the events file.

example

local typingFile; typingFile=${ makeTempFile; }
asciinemaTypingFile 120 '[rayvn]$ ' 'rayvn test' "${typingFile}"

asciinemaPostProcess()

Post-process an asciinema cast file in-place: prepend typing events and optionally trim the terminal dimensions in the header to fit the actual content.

args


`castFile` (string)	Path to the cast file (modified in-place).
`typingFile` (string)	Path to a file of asciinema event lines to prepend.
`trim` (int)	1 to trim header dimensions to content (default: 1), 0 to skip.

notes

Supports both v2 (absolute timestamps) and v3 (relative/delta timestamps). For v2, original event timestamps are shifted by the total typing duration. For v3, typing events are simply prepended (already in delta format). Trimmed cols are at least 106 to ensure comfortable display in web players.

asciinemaApplyTransform()

Apply a single named post-processing transform to a cast file in-place. Run transforms one at a time to inspect the cast between steps.

args


`transform` (string)	Which transform to apply (name or step number 1–9).
`castFile` (string)	Cast file to transform in-place.

options

–cmd TEXT Command text shown in typing prelude (required for prepend-typing). –prompt TEXT Shell prompt text (default: ‘[rayvn]$ ‘). –wpm N Typing speed in words per minute (default: 120).

steps

1 filter-input Strip “i” events; fold their delta into the next event. 2 prepend-typing Insert simulated typing prelude (requires –cmd). 3 strip-cleanup Remove widget dropdown-close sequences before cursor-restore. 4 inject-clear Insert \u001b[J] (clear screen) after selection result. 5 append-prompt Append trailing shell prompt event. 6 patch-header Strip recorder fields; compute and update dimensions. 7 insert-cursor-hide Add \u001b[?25l] before exit event. 8 fix-positions Shift widget absolute rows by (1 - record_row). 9 shift-typing-rows Shift widget rows down by the number of pre-CPR newlines.

asciinemaMarkup()

Print a Jekyll asciinema include tag for a cast file. Walks up from the cast file’s directory to find a Jekyll root (_config.yml) and computes the web-relative src path automatically.

args


`castFile` (string)	Path to the cast file.

output

A  comment and {% include asciinema.html ... %} tag ready to paste into a markdown file.

example

asciinemaMarkup /path/to/assets/casts/test.cast