vis-menu.1

.Dd November 29, 2016
.Dt VIS-MENU 1
.Os Vis VERSION
.Sh NAME
.Nm vis-menu
.Nd Interactively select an item from a list
.
.Sh SYNOPSIS
.Nm vis-menu
.Op Fl i
.Op Fl t | Fl b
.Op Fl p Ar prompt
.Op Fl l Ar lines
.Op Ar initial
.Nm vis-menu
.Op Fl v
.
.Sh DESCRIPTION
.Nm vis-menu
allows a user to interactively select one item from a list of options.
A newline-separated list of items is read from standard input,
then the list of items is drawn directly onto the terminal
so the user may select one.
Finally,
the selected item is printed to standard output.
.Pp
For information on actually navigating the menu,
see
.Sx USAGE
below.
.Bl -tag -width flag
.It Fl i
Use case-insensitive comparison when filtering items.
.It Fl t | Fl b
Normally,
the menu is displayed on the current line of the terminal.
When
.Fl t
is provided, the menu will always be drawn on the top line of the terminal.
When
.Fl b
is provided, the menu will always be drawn on the bottom line.
.It Fl p Ar prompt
Display
.Ar prompt
before the list of items.
.It Fl l Ar lines
Normally,
the list is displayed with all the items side-by-side on a single line,
which is space-efficient
but does not show many items at a time,
especially if some of them are long.
When
.Fl l
is provided,
the list is displayed with each item on its own line,
.Ar lines
lines high.
If there are more than
.Ar lines
items in the list,
the user can scroll through them with the arrow keys,
just like in the regular horizontal mode.
.It Ar initial
The user can type into a text field
to filter the list of items
as well as scrolling through them.
If supplied,
.Ar initial
is used as the initial content of the text field.
.It Fl v
Instead of displaying an interactive menu,
.Nm vis-menu
prints its version number to standard output and exits.
.El
.
.Sh USAGE
.Nm vis-menu
displays the prompt (if any),
a text field,
and a list of items.
Normally these are presented side-by-side in a single line,
but if the
.Fl l
flag is given,
the prompt and typing area will be on the first line,
and list items on the following lines.
.Pp
The following commands are available:
.Bl -tag -width ".Sy Control-A"
.It Sy Enter
selects the currently-highlighted list item and exits.
.It Xo Sy Control-\e
or
.Sy Control-]
.Xc
selects the current contents of the text field
(even if it does not appear in the list)
and exits.
.It Xo Sy "ESC ESC"
or
.Sy Control-C
.Xc
exit without selecting any item.
.It Xo Sy Down
or
.Sy Control-N
.Xc
scroll forward through the available list items.
.It Xo Sy Up
or
.Sy Control-P
.Xc
scroll backward through the available list items.
.It Xo Sy Right
or
.Sy Control-F
.Xc
move the cursor forward through the typed text,
and scroll through the available list items.
.It Xo Sy Left
or
.Sy Control-B
.Xc
move the cursor backward through the typed text,
and scroll through the available list items.
.It Xo Sy PageUp
or
.Sy Control-V
.Xc
scrolls to show the previous page of list items.
.It Xo Sy PageDown
or
.Sy Meta-v
.Xc
scrolls to show the next page of list items.
.It Xo Sy Home
or
.Sy Control-A
.Xc
move the cursor to the beginning of the text field
or scroll to the first item in the list.
.It Xo Sy End
or
.Sy Control-E
.Xc
move the cursor to the end of the text field
or scroll to the last item in the list.
.It Sy Meta-b
moves the cursor to the beginning of the current word in the text field.
.It Sy Meta-f
moves the cursor past the end of the current word in the text field.
.It Sy Tab
copies the content of the selected list item into the text field.
This is almost, but not quite, like tab completion.
.It Xo Sy Delete
or
.Sy Control-D
.Xc
delete the character in the text field under the cursor.
.It Sy Backspace
deletes the character in the text field to the left of the cursor.
.It Sy Meta-d
deletes the characters in the text field
from the character under the cursor
to the next space.
.It Sy Control-K
deletes the characters in the text field
from the character under the cursor to the end.
.It Sy Control-U
deletes the characters in the text field
from the beginning up to
(but not including)
the character under the cursor.
.It Sy Control-W
deletes the characters in the text field
from the previous space up to
(but not including)
the character under the cursor.
.El
.Pp
All other non-control characters will be inserted into the text field
at the current cursor position.
.Pp
When there is text in the text field,
only list items that include the given text will be shown.
If the text contains one or more spaces,
each space-delimited string is a separate filter
and only items matching every filter will be shown.
.Pp
If the user filters out all the items from the list,
then hits Enter to select the
.Dq currently highlighted
item,
the text they typed will be returned instead.
.
.Sh EXAMPLES
Here's a shell-script that allows the user to choose a number from one to 10:
.Bd -literal -offset indent
NUMBER=$(seq 1 10 | vis-menu -p "Choose a number")
if [ $? -eq 0 ]; then
	echo "You chose: $NUMBER"
else
	echo "You refused to choose a number, or an error occurred."
fi
.Ed
.
.Sh DIAGNOSTICS
The
.Nm vis-menu
utility exits 0 if the user successfully selected an item from the list,
and 1 if the user cancelled.
.Pp
If an internal error occurs,
the
.Nm vis-menu
utility prints a message to standard error and exits 1.
Potential error conditions include
being unable to allocate memory,
being unable to read from standard input,
or being run without a controlling terminal.
.
.Sh SEE ALSO
.Xr dmenu 1 ,
.Xr slmenu 1 ,
.Xr vis 1
.
.Sh HISTORY
The original model for a single line menu reading items from standard input was
.Xr dmenu 1
which implements the idea for X11.
.Nm dmenu
is available from
.Li http://tools.suckless.org/dmenu/
.Pp
The code was subsequently re-worked for ANSI terminal output as
.Xr slmenu 1
which is available from
.Li https://bitbucket.org/rafaelgg/slmenu/
.Pp
Since
.Nm slmenu
did not appear to be maintained,
it was forked to become
.Nm vis-menu
to be distributed with
.Xr vis 1 .