These are environment variables and options that uses may set, to modify the behavior of cli.

User facing environment variables

Set to posix to force generating POSIX compatible ANSI hyperlinks. If not set, then RStudio compatible links are generated. This is a temporary crutch until RStudio handles POSIX hyperlinks correctly, and after that it will be removed.

NO_COLOR

Set to a nonempty value to turn off ANSI colors. See [num_ansi_colors()].

ESS_BACKGROUND_MODE

Set this environment variable to light or dark to indicate dark mode in Emacs. Once https://github.com/emacs-ess/ESS/pull/1178 is merged, ESS will set this automatically.

R_CLI_DYNAMIC

Set to true, TRUE or True to assume a dynamic terminal, that supports \r. Set to anything else to assume a non-dynamic terminal. See [is_dynamic_tty()].

R_CLI_NUM_COLORS

Set to a positive integer to assume a given number of colors. See [num_ansi_colors()].

Set to true, TRUE or True to tell cli that the terminal supports ANSI hyperlinks. Set to anything else to assume no hyperlink support. See [style_hyperlink()].

User facing options

cli.ansi

Set to true, TRUE or True to assume a terminal that supports ANSI control sequences. Set to anything else to assume a non-ANSI terminal. See [is_ansi_tty()].

cli.condition_unicode_bullets

TRUE or FALSE to force turn on or off the Unicode symbols when printing conditions. E.g. in format_error(), format_warning(), format_message() and also in cli_abort(), cli_warn() and cli_inform().

cli.condition_width

Integer scalar (or Inf) to set the console width when cli is formatting errors, warnings or messages in format_error(), format_warning() and format_message(). When formatting conditions this option takes precedence over cli.width.

cli.default_handler

General handler function for all cli conditions. See https://cli.r-lib.org/articles/semantic-cli.html#cli-messages-1

cli.default_num_colors

Default number of ANSI colors. This value is only used if ANSI color support is detected. You can set this value to keep relying on auto-detection, but to adjust the number of colors when cli detects color support. See [num_ansi_colors()]. See also the cli.num_colors option.

cli.dynamic

Set to TRUE to assume a dynamic terminal, that supports \r. Set to anything else to assume a non-dynamic terminal. See [is_dynamic_tty()].

cli.hide_cursor

Whether the cli status bar should try to hide the cursor on terminals. Set the FALSE if the hidden cursor causes issues.

Set to true, TRUE or True to tell cli that the terminal supports ANSI hyperlinks. Set to anything else to assume no hyperlink support. See [style_hyperlink()].

cli.ignore_unknown_rstudio_theme

Set to TRUE to omit a warning for an unknown RStudio theme in code_highlight().

cli.num_colors

Number of ANSI colors. See [num_ansi_colors()]. See also the cli.default_num_colors option.

cli.message_class

Character vector of classes to add to cli’s conditions.

cli.progress_bar_style

Progress bar style. See [cli_progress_styles()].

cli.progress_bar_style_ascii

Progress bar style on ASCII consoles. See [cli_progress_styles()].

cli.progress_bar_style_unicode

Progress bar style on Unicode (UTF-8) consoles; See [cli_progress_styles()].

cli.progress_clear

Whether to clear terminated progress bar from the screen on dynamic terminals. See [cli_progress_bar()].

cli.progress_demo_live

Whether cli_progress_demo() should show a live demo, or just record the progress bar frames.

cli.progress_format_download

Default format string for download progress bars.

cli.progress_format_download_nototal

Default format string for download progress bars with unknown totals.

cli.progress_format_iterator

Default format string for iterator progress bars.

cli.progress_format_iterator_nototal

Default format string for iterator progress bars with unknown total number of progress units.

cli.progress_format_tasks

Default format string for tasks progress bars.

cli.progress_format_tasks_nototal

Default format string for tasks progress bars with unknown totals.

cli.progress_handlers

Progress handlers to try. See [cli_progress_builtin_handlers()].

cli.progress_handlers_force

Progress handlers that will always be used, even if another handler was already selected. See [cli_progress_builtin_handlers()].

cli.progress_handlers_only

Progress handlers to force, ignoring handlers set in cli.progress_handlers and cli.progress_handlers_force. See [cli_progress_builtin_handlers()].

cli.progress_say_args

Command line arguments for the say progress handlers. See [cli_progress_builtin_handlers()].

cli.progress_say_command

External command to use in the say progress handler. See [cli_progress_builtin_handlers()].

cli.progress_say_frequency

Minimum delay between say calls in the say progress handler. say ignores very frequent updates, to keep the speech comprehensible. See [cli_progress_builtin_handlers()].

cli.progress_show_after

Delay before showing a progress bar, in seconds. Progress bars that finish before this delay are not shown at all. cli also shows progress bars that have more than 50% to go after half of this delay has passed.

cli.spinner

Default spinner to use, see [get_spinner()].

cli.spinner_ascii

Default spinner to use on ASCII terminals, see [get_spinner()].

cli.spinner_unicode

Default spinner to use on Unicode terminals, see [get_spinner()].

cli.theme

Default cli theme, in addition to the built-in theme. This option in intended for the package developers. See [themes] and [start_app()].

cli.theme_dark

Whether cli should assume a dark theme for the builtin theme. See [builtin_theme()].

cli.unicode

Whether to assume a Unicode terminal. If not set, then it is auto-detected. See [is_utf8_output()].

cli.user_theme

cli user theme. This option is intended for end users. See [themes].

cli.warn_inline_newlines

Whether to emit a warning when cli replaces newline characters with spaces within a {.class } inline style. Defaults to FALSE.

cli.width

Terminal width to assume. If not set, then it is auto-detected. See [console_width()].

rlib_interactive

Whether to assume an interactive R session. If not set, then it is auto-detected.

width

Terminal width. This is used on some platforms, if cli.width is not set.