What's new in 3.2¶

hellish 3.2 is about the prompt. The up arrow finds what you started typing. A dim hint from your history can complete the line, and you take it with one key. make <TAB> knows your targets, and bind puts a shell command on a key. This page shows how to use each one. Every example on it was run on a 3.2 build.

Get it

Already running hellish? Type update --now. Otherwise install it:

curl -fsSL https://raw.githubusercontent.com/Univers42/hellish/main/install.sh | sh

At a glance¶

This is the table from the welcome banner, explained.

Keys	What it does	Needs
`↑ ↓`	history by prefix	on by default
`make <TAB>`	Makefile targets
`bind -x`	key runs a command
`bindkey`	zsh binds now work	zsh mode
`${var@P}`	render as a prompt
`$SRANDOM`	and `$EPOCHREALTIME`
`→ ^F End`	take the dim hint	`HELLISH_AUTOSUGGEST=1`
`Alt-F`	take one word	`HELLISH_AUTOSUGGEST=1`
`Alt-N/P`	older/newer hint	`HELLISH_AUTOSUGGEST=1`

History that matches what you typed¶

Type the start of a command, then press ↑. Up now steps only through history lines that begin with the text before the cursor, and ↓ steps back toward the newest one:

$ git<Up>          ->  git push      the newest line starting with "git"
$ git<Up><Up>      ->  git status    the one before it

On an empty line, Up and Down walk the whole history as before.

It is on by default. HELLISH_HISTORY_PREFIX=0 (or off) brings back plain Up/Down. The variable is read at every prompt, so you can change it in the middle of a session.
Configs that already asked for this now get it. That covers bash's bind '"\e[A": history-search-backward', zsh's bindkey '^[[A' history-beginning-search-backward, and oh-my-zsh's up-line-or-beginning-search. Before 3.2, each of them left the arrow dead.
A key you bound yourself keeps your binding.

Inline hints¶

Hints are off until you ask for them. Add this line to ~/.hellishrc, or type it at the prompt to try it:

export HELLISH_AUTOSUGGEST=1

From then on, when you type the start of a line you ran before, the rest of it appears dimmed after the cursor. The hint is the newest history line that starts with what you typed. It is not part of your line until you take it:

$ echo hello          ran earlier
$ ech|o hello         you typed "ech", the cursor is at |, "o hello" is dim

Key	What it does
`→`, `End` or `Ctrl-F`	take the whole hint
`Alt-F` or `Ctrl-→`	take its next word
`Alt-N` / `Alt-P`	show an older / a newer match instead
`Enter`	run only what you typed

With no hint on screen, these keys keep their usual job: Right moves the cursor, Alt-F moves a word, and Alt-N / Alt-P are readline's history search.
A word is the hint's leading blanks plus the text up to the next space or tab.
Cycling skips duplicates. It stops at either end with a bell instead of wrapping around. Any edit starts again from the newest match.
Hints also work in vi insert mode.
A history line that holds a newline or a control character is never offered. A terminal that cannot move the cursor (TERM unset or dumb) never shows a hint.
HELLISH_SUGGEST_MAX=N sets how many of the newest history lines are searched (default 1000).
In zsh mode, widgets see the hint as POSTDISPLAY, and can set their own.

Completing make targets¶

Tab after make offers the targets of the Makefile in the current directory. With this Makefile:

.PHONY: all clean fclean re
NAME = demo
all: $(NAME)
$(NAME): main.o
    cc -o $@ $^
%.o: %.c
    cc -c $<
clean:
    rm -f *.o
fclean: clean
    rm -f $(NAME)
re: fclean all

$ make <TAB><TAB>
all     clean   fclean  re
$ make fc<TAB>
$ make fclean

The variable, the pattern rule, $(NAME) and .PHONY are not targets you would type, so they are not offered.

The shell reads the file itself; make is never run. It reads the first of GNUmakefile, makefile and Makefile (the order GNU make uses).
It also works for gmake and /usr/bin/make, and after sudo, env X=1, && or (.
include lines are followed one level deep. If you change only an included file, the list is not refreshed: touch the Makefile.
With no Makefile, Tab completes file names as usual.

The full rules are in the manual's make targets section.

Key bindings with bind¶

hellish now has bash's bind builtin, so the lines you would put in ~/.inputrc work in ~/.hellishrc:

bind '"\e[A": history-search-backward'     # a key -> a readline command
bind 'set completion-ignore-case on'        # a readline setting
bind -x '"\C-t": date'                       # a key -> a shell command

bind -x runs the command the way bash does. It can read and change the line you are editing through READLINE_LINE and READLINE_POINT (the cursor). This key puts sudo in front of the line and leaves the cursor at the end:

bind -x '"\C-xs": READLINE_LINE="sudo $READLINE_LINE"; READLINE_POINT=${#READLINE_LINE}'

$ apt update<Ctrl-X s>
$ sudo apt update

To see what is bound: bind -p lists key bindings, bind -v the settings, bind -X the -x commands and bind -l every command name. help bind shows every option.

bindkey in zsh configs¶

In zsh mode (set -o zsh, emulate zsh, or a sourced .zsh file), bindkey now understands zsh's key notation (^[[A, ^R, ^[b, \E) and reaches the line editor's own widgets. These two lines from a zsh config now do what they say:

bindkey '^[[A' history-beginning-search-backward
bindkey '^[[B' history-beginning-search-forward

Rendering text like the prompt¶

${var@P} expands a value the way the prompt does. It uses the same renderer as PS1, so the result always matches your prompt:

$ USER=ada; PS1='\u in \W \$ '; cd /usr/share
$ echo "${PS1@P}"
ada in share $

Both escape languages work, bash's \u \w and zsh's %n %~. prompt preview uses it to draw the themes.

Two new variables¶

$ echo $SRANDOM
2414656789
$ echo $EPOCHREALTIME
1792288722.298309

$SRANDOM is a 32-bit random number, a new one each time you read it. $EPOCHREALTIME is the time in seconds since the epoch, with microseconds. Both come from bash: $EPOCHREALTIME from 5.0, $SRANDOM from 5.1.

Fixed¶

At the prompt:

On some builds, the hint keys did nothing and Up did not search by prefix: the keys kept their stock behaviour. They now work on every build.
Two small memory leaks in line editing are fixed. One came from walking history with Up or Ctrl-P and then pressing Enter or Ctrl-C; the other from cancelling an Alt-P search.
In zsh mode, pressing Esc twice (oh-my-zsh's sudo plugin) printed builtin: which: not a shell builtin. which [-ap] name now exists in zsh mode.
PS2 is the prompt of every continuation line.
A Ctrl-C at the wrong moment no longer eats the next key.

In scripts:

exec nosuch no longer crashes the shell.
A runtime error names the line it happened on, and a command that cannot run says why, in bash's words and with bash's exit status.
read assigns its variables at end of input, and never a readonly one.
A quoted "$@" element is never expanded as a glob pattern.
export X before X is set keeps the export.
Heredocs work inside function bodies, eval and source.

Installing and building:

The curl … | sh installer prints the complete PATH instruction (#164).
make re no longer stops on NFS when a hellish from build/ is still running.

Every change since 3.1.3: v3.1.3...v3.2.0.