w64devkit/man/man1/reset.1

.TH RESET 1 2026-10-19 "w64devkit" "w64devkit Manual"
.SH NAME
reset \- reset the console's text attributes and clear its screen
.SH SYNOPSIS
.B reset
.RB [ \-\-help ]
.SH DESCRIPTION
.B reset
cleans up a console that a program has left in a bad state.
When standard output is a console, it does three things in order:
.IP 1. 4
It writes
.RB ESC\  [m ,
which resets the text attributes, such as color and bold.
.IP 2. 4
It writes
.RB ESC\  [?1049l ,
which leaves the alternate screen buffer.
.IP 3. 4
It moves the cursor to the top left corner of the console's screen
buffer, then fills the whole buffer with spaces.
.PP
When standard output is not a console, such as a file, a pipe, or the
.B NUL
device, nothing is written and nothing is changed.
Whether standard input or standard error is a console does not matter.
.PP
When the console has virtual terminal processing enabled, it interprets
the two sequences; see
.BR BB_TERMINAL_MODE .
Otherwise busybox emulates them through the console API.
The third step always uses the console API.
.PP
The fill, and an emulated
.RB ESC\  [m ,
use the text attributes that the console had when this busybox process
first used it.
The kit's
.B sh
runs
.B reset
within itself, so in an interactive shell these are the attributes from
before its first prompt, not any that a program has set since.
Run as a process of its own, as from
.BR cmd.exe ,
.B reset
first uses the console when it writes the two sequences, so the fill
uses whatever colors a program left behind, and an emulated
.RB ESC\  [m
changes nothing.
.PP
An emulated
.RB ESC\  [?1049l
leaves only an alternate buffer that the same process entered with an
emulated
.RB ESC\  [?1049h ,
such as one written by the shell's own
.B echo
or
.BR printf ,
and not one that another program entered.
.SH OPTIONS
.B reset
takes no options.
It ignores its arguments, unless the first is
.BR \-\-help .
.TP
.B \-\-help
Print a usage message on standard output and exit.
The message describes the Unix build; see
.BR NOTES .
.SH ENVIRONMENT
Run as a process of its own,
.B reset
reads these variables only when standard output is a console.
When the shell runs
.B reset
itself, the shell's current mode applies, and an assignment before the
command, as in
.BR "BB_TERMINAL_MODE=0 reset" ,
has no effect on it.
.TP
.B BB_TERMINAL_MODE
How busybox handles escape sequences written to a console.
With
.B 0
or
.BR 2 ,
it disables the console's virtual terminal processing and emulates the
sequences itself.
With
.B 1
or
.BR 3 ,
it enables virtual terminal processing and passes the sequences
through, even if the console cannot interpret them.
With
.BR 4 ,
it passes them through if the console already has virtual terminal
processing enabled, and otherwise emulates them.
With
.BR 5 ,
it enables virtual terminal processing if the console supports it, and
otherwise emulates the sequences.
A number outside 0 to 5 means
.BR 5 ,
and text that is not a number means
.BR 0 .
.TP
.B BB_SKIP_ANSI_EMULATION
Used when
.B BB_TERMINAL_MODE
is unset:
.B 1
means mode
.BR 1 ,
.B 2
means mode
.BR 5 ,
and any other value means mode
.BR 0 .
.TP
.B CONEMUPID
When neither of the above is set, the mode is
.BR 5 ,
or
.B 0
if
.B CONEMUPID
is set, as under ConEmu, or when running under Wine.
.PP
The busybox startup code also reads
.BR BB_CRITICAL_ERROR_DIALOGS ,
.BR BB_GLOBBING ,
and
.BR BB_UMASK ,
and console output reads
.BR LC_ALL ,
.BR LC_CTYPE ,
and
.BR LANG ,
none of which changes what
.B reset
does; see
.BR busybox (1).
.SH EXIT STATUS
.TP
.B 0
Success.
Errors from the console are ignored.
.TP
.B 141
The
.B \-\-help
message was written to a pipe whose reader has exited.
.SH EXAMPLES
Clean up after a program that left the console in odd colors:
.PP
.RS 4
.EX
$ reset
.EE
.RE
.PP
Standard output is not a console, so nothing is written:
.PP
.RS 4
.EX
$ reset >out.txt
$ wc \-c <out.txt
0
.EE
.RE
.SH NOTES
Differences from the ncurses
.BR reset :
.IP \(bu 2
It takes no options or terminal type, ignores its arguments instead of
rejecting them, and does not use
.B TERM
or terminfo.
.IP \(bu 2
It does not reset the terminal modes as the Unix build does with
.BR "stty sane" ,
although its usage message says it does.
The console's input mode is not changed.
.IP \(bu 2
It does not make a hidden cursor visible.
.PP
Unlike
.BR clear ,
which writes its sequence even to a pipe or file,
.B reset
writes nothing unless standard output is a console.
.B clear
clears only the visible window, and
.B reset
clears the whole screen buffer.
.PP
In a classic console window the screen buffer holds the scrollback, so
.B reset
erases the history, and the window then shows the top of the buffer.
A terminal that keeps its own scrollback, such as Windows Terminal,
keeps it: there,
.B reset
clears only the visible screen.
.PP
Run as a process of its own,
.B reset
also adjusts the console as any busybox command does when it first
writes an escape sequence there: it turns virtual terminal processing on
or off as
.B BB_TERMINAL_MODE
says, clears
.BR DISABLE_NEWLINE_AUTO_RETURN ,
replaces an output mode of 0 with processed output and line wrapping,
and changes code page 850 to 858; see
.BR busybox (1).
An interactive
.B sh
sets the output mode the same way before each prompt.
.PP
The kit's
.B sh
runs
.B reset
inside the shell process, without starting a new one, except where the
shell needs a separate process anyway, as for a command substitution or
a pipeline.
In a command substitution standard output is a pipe, so
.B reset
does nothing there.
When it runs inside the shell and its
.B \-\-help
message goes to a pipe whose reader has exited, it ends the shell
itself with status 141.
.SH SEE ALSO
.BR busybox (1),
.BR clear (1),
.BR sh (1)