Select from zsh completion menu by number - zsh

I discovered this little navigation trick the other day, which allows me to trigger menu completions by number when I enter 'cd -'
~ cd -
0 -- ~/home
1 -- ~/home/stuff
2 -- ~/downloads
3 -- ~/wallpaper
Shell scripting syntax still reads like a foreign language to me, but to get this functionality my directory stack history is piped into the function below.
DIRSTACKSIZE=9
DIRSTACKFILE=~/.zdirs
if [[ -f $DIRSTACKFILE ]] && [[ $#dirstack -eq 0 ]];
then dirstack=( ${(f)"$(< $DIRSTACKFILE)"} )
[[ -d $dirstack[1] ]] && cd $dirstack[1] && cd $OLDPWD
fi
chpwd() {
print -l $PWD ${(u)dirstack} >$DIRSTACKFILE
}
The magical part is being able to choose from the list by number, but I have come to learn that this is probably
because the functionality for navigation by number is baked in to the 'cd -' command. Still, I'd like to use this everywhere.
Any tips writing a wrapper function (or something like that, I guess) for the completion menu that pipes in completions from the menu when it is triggered
and displays them in a numbered list where those numbers select the corresponding element?
I've gotten started reading the manual and what not, but everything remains rather opaque. Thanks!

First off, the code snippet you show has nothing to do with completion. Instead, what it does is to record the directory stack to a file in order to preserve it between zsh sessions. (Personally, I'm not even sure this is a good idea.)
A good place to start investigating zsh completions is the _complete_help ZLE widget. This is bound by default to ^Xh in zsh's viins (vi insert) keyboard map, but is unbound by default in the emacs keymap. If you want to use it in the emacs keymap (the default for many people), you have to bind it:
bindkey -M emacs "^Xh" _complete_help
Now you can type cd - (or cd +) and follow it by CTRL-Xh instead of TAB. You should see the following output:
tags in context :completion::complete:cd::
directory-stack (_directory_stack _cd)
(At this point I'll admit we're getting close to the limits of my knowledge of the zsh completion system.)
Now you can see the completer functions for the directory-stack tag in this particular context. The one you're probably interested in is _directory_stack, and you can see the content of that function with:
functions _directory_stack
…which is where those leading numbers are actually generated.
Arguably it's possible to write similar completion functions for other completion contexts, and apply the using zstyle. However, this is non-trivial completion magic, and beyond anything I have attempted

Related

Sourcing Alias Prevents Less Buffer From Displaying

I'm writing a bash script that needs to both be able to cd in the current shell and use less to display longform text. To be able to cd, I understand that I need to source the script when I call it, which I've done via an alias in my ZSH config. However, when I do this, less breaks: instead of echo -e "$result" | less displaying its usual scrolling buffer, the long text gets dumped into the shell.
For context, this is a bash script acting as a wrapper for a Node.js script so as to be able to have native access to bash commands (like cd, open, etc.). The alias in my zshrc is as follows (with the path truncated): alias bk='source ~/.../bookmark/bookmark.sh'.
Is there any way to satisfy both the need to cd and the need to use less?
Fixed! This turned out to be an issue in my script's logic. I was using condition=$(echo $result | cut -c 1-3), but in reality need the first three characters (not columns) of $result, which I then did by using $result | head -c 3. What's interesting about this is that fetching the first three columns from $result when determined by running ./bookmark.sh works as an equivalent to fetching the first three characters, but running the alias yields the issue here.

Simple command completion using _alternative in zsh

Finally getting around to switching to zsh (from bash)... I'm trying to understand a bit more about the completion system and could use a quick pointer. I have been able to get other completions to work for command arguments, but I'm struggling with path completions.
I use a simple function (cdp) to jump to project directories. I've set up a very basic completion script, which almost works. I just can't seem to get the behavior that I'm hoping for.
Ideally, typing cdp in{tab} would expand to all projects starting with in, such as:
~/Projects/indigo ~/Projects/instant
Instead, I can only get cdp {tab} to get the ~/Projects path. From there, it will expand the first-level directory. I'd like to be able to just run standard completion for cd once the project directory is expanded.
Here is the completion script, save in _cdp and added to fpath:
#compdef cdp
basedir="$HOME/Projects"
# the function for jumping to directories...
cdp() {
if [ -z "$1" ] ; then
cd $basedir
else
cd "$1"
fi
}
# completion helper...
_alternative "directories:user directory:($basedir/*)"
It's pretty basic, I'm just stuck trying to sort out where to go next. Any thoughts or pointers would be great. Thanks!
UPDATE
I'm finding that cdpath works fine for most of what I need... It would still be interesting to know how to complete this simple function, but for now at least I have a working solution using cdpath and auto_cd.

Zsh: How to force file completion everywhere following a set of characters?

I'm trying to figure out how to get file completion to work at any word position on the command line after a set of characters. As listed in a shell these characters would be [ =+-\'\"()] (the whitespace is tab and space). Zsh will do this, but only after the backtick character, '`', or $(. mksh does this except not after the characters [+-].
By word position on the command line, I'm talking about each set of characters you type out which are delimited by space and a few other characters. For example,
print Hello World,
has three words at positions 1-3. At position 1, when you're first typing stuff in, completion is pretty much perfect. File completion works after all of the characters I mentioned. After the first word, the completion system gets more limited since it's smart. This is useful for commands, but limiting where you can do file completion isn't particularly helpful.
Here are some examples of where file completion doesn't work for me but should in my opinion:
: ${a:=/...}
echo "${a:-/...}"
make LDFLAGS+='-nostdlib /.../crt1.o /.../crti.o ...'
env a=/... b=/... ...
I've looked at rebinding '^I' (tab) with the handful of different completion widgets Zsh comes with and changing my zstyle ':completion:*' lines. Nothing has worked so far to change this default Zsh behaviour. I'm thinking I need to create a completion function that I can add to the end of my zstyle ':completion:*' completer ... line as a last resort completion.
In the completion function, one route would be to cut out the current word I want to complete, complete it, and then re-insert the completion back into the line if that's possible. It could also be more like _precommand which shifts the second word to the first word so that normal command completion works.
I was able to modify _precommand so that you can complete commands at any word position. This is the new file, I named it _commando and added its directory to my fpath:
#compdef -
# precommands is made local in _main_complete
precommands+=($words[1,$(( CURRENT -1 ))])
shift words
CURRENT=1
_normal
To use it I added it to the end of my ':completion:*' completer ... line in my zshrc so it works with every program in $path. Basically whatever word you're typing in is considered the first word, so command completion works at every word position on the command line.
I'm trying to figure out a way to do the same thing for file completion, but it looks a little more complicated at first glace. I'm not really sure where to go with this, so I'm looking to get some help on this.
I took a closer look at some of Zsh's builtin functions and noticed a few that have special completion behaviour. They belong to the typeset group, which has a function _typeset in the default fpath. I only needed to extract a few lines for what I wanted to do. These are the lines I extracted:
...
elif [[ "$PREFIX" = *\=* ]]; then
compstate[parameter]="${PREFIX%%\=*}"
compset -P 1 '*='
_value
...
These few lines allow typeset completion after each slash in a command like this:
typeset file1=/... file2=~/... file3=/...
I extrapolated from this to create the following function. You can modify it to put in your fpath. I just defined it in my zshrc like this:
_reallyforcefilecompletion() {
local prefix_char
for prefix_char in ' ' $'\t' '=' '+' '-' "'" '"' ')' ':'; do
if [[ "$PREFIX" = *${prefix_char}* ]]; then
if [[ "$PREFIX" = *[\'\"]* ]]; then
compset -q -P "*${prefix_char}"
else
compset -P "*${prefix_char}"
fi
_value
break
fi
done
}
You can use this by adding it to a zstyle line like this:
zstyle ':completion:*' completer _complete _reallyforcefilecompletion
This way, it's only used as a last resort so that smarter completions can try before it. Here's a little explanation of the function starting with the few variables and the command involved:
prefix_char: This gets set to each prefix character we want to complete after. For example, env a=123 has the prefix character =.
PREFIX: Initially this will be set to the part of the current word from the beginning of the word up to the position of the cursor; it may be altered to give a common prefix for all matches.
IPREFIX (not shown in code): compset moves string matches from PREFIX to IPREFIX so that the rest of PREFIX can be completed.
compset: This command simplifies modification of the special parameters, while its return status allows tests on them to be carried out.
_value: Not really sure about this one. The documentation states it plays some sort of role in completion.
Documentation for the completion system
The function: In the second line, we declare prefix_char local to avoid variable pollution. In line three, we start a for loop selecting each prefix_char we want to complete after. In the next if block, we check if the variable PREFIX ends with one of the prefix_chars we want to complete after and if PREFIX contains any quotes. Since PREFIX contains quotes, we use compset -q to basically allow quotes to be ignored so we can complete in them. compset -P strips PREFIX and moves it to IPREFIX, basically so it gets ignored and completion can work.
The next elif statement is for a PREFIX ending with prefix_char but not containing quotes, so we only use compset -P. I added the return 0 to break the loop. A more correct way to make this function would be in a case statement, but we're not using the compset return value, so this works. You don't see anything about file completion besides _value. For the most part we just told the system to ignore part of the word.
Basically this is what the function does. We have a line that looks like:
env TERM=linux PATH=/<---cursor here
The cursor is at the end of that slash. This function allows PREFIX, which is PATH=, to be ignored, so we have:
env TERM=linux /<---cursor here
You can complete a file there with PATH= removed. The function doesn't actually remove the PATH= though, it just recategorizes it as something to ignore.
With this function, you can now complete in all of the examples I listed in the question and a lot more.
One last thing to mention, adding this force-list line in your zshrc cripples this function somehow. It still works but seems to choke. This new force-list function is way better anyway.
zstyle ':completion:*' force-list always
EDIT: There were a couple lines I forgot to copy into the function. Probably should have checked before posting. I think it's good now.

Make zsh complete arguments from a file

zsh is great but its completion system is very diverse. And the documentation lacks good examples. Is there a template for completing for a specific application. The completion would get its match data from a file, separated by newlines?
I tried modifying an older example of mine that takes match data "live":
~ % cat .zsh/completers/_jazzup
#compdef jazz_up
_arguments "2: :(`mpc lsplaylists|sed -e 's# #\\\\ #g'`)"
I could supply cat my_file there instead of mpc invocation and so on but would there be a more elegant way to do this simple task? And that completion there is placement-specific: can you provide an example where zsh would attempt to complete at any point after the program name is recognized?
The match data will have whitespaces and so on, the completion should escape the WS. Example of that:
Foo bar
Barbaric
Get it (42)
Now if that completion would be configured for a command Say, we should get this kind of behaviour out of zsh:
$ Say Fo<TAB>
$ Say Foo\ bar
$ Say Ge<TAB>
$ Say Get\ it\ \(42\)
Simple completion needs are better addressed with _describe, it pairs an array holding completion options and a description for them (you can use multiple array/description pairs, check the manual).
(_arguments is great but too complex.)
[...]
First create a file
echo "foo\nbar\nbaz\nwith spac e s\noh:noes\noh\:yes" >! ~/simple-complete
Then create a file _simple somewhere in your $fpath:
#compdef simple
# you may wish to modify the expansion options here
# PS: 'f' is the flag making one entry per line
cmds=( ${(uf)"$(< ~/simple-complete)"} )
# main advantage here is that it is easy to understand, see alternative below
_describe 'a description of the completion options' cmds
# this is the equivalent _arguments command... too complex for what it does
## _arguments '*:foo:(${cmds})'
then
function simple() { echo $* }
autoload _simple # do not forget BEFORE the next cmd!
compdef _simple simple # binds the completion function to a command
simple [TAB]
it works. Just make sure the completion file _simple is placed somewhere in your fpath.
Notice that : in the option list is supposed to be used for separating an option from their (individual) description (oh:noes). So that won't work with _describe unless you quote it (oh\:yes). The commented out _arguments example will not use the : as a separator.
Without changing anything further in .zshrc (I already have autoload -Uz compinit
compinit) I added the following as /usr/local/share/zsh/site-functions/_drush
#compdef drush
_arguments "1: :($(/usr/local/bin/aliases-drush.php))"
Where /usr/local/bin/aliases-drush.php just prints a list of strings, each string being a potential first argument for the command drush. You could use ($(< filename)) to complete from filename.
I based this on https://unix.stackexchange.com/a/458850/9452 -- it's surprising how simple this is at the end of the day.

tmux man-page search highlighting

When I search in, for example, man ls while in a tmux session, the search strings don't appear highlighted - the page jumps down so that the search string is on the top line of the buffer, as expected, but it's not highlighted.
Doing the same thing in the same shell while not in a tmux session results in highlighted search strings.
I have no idea where to start looking to solve this. Any hints are appreciated.
Based on Less Colors For Man Pages by Gen2ly, here is my man page and how to do it:
Preview
This is a shell, not a web page !
How to
(optional) I'm using Tomorrow theme for Konsole/Yakuake ;
Edit your ~/.bashrc ~/.zshrc, etc. to add :
# Colored man pages: http://linuxtidbits.wordpress.com/2009/03/23/less-colors-for-man-pages/
# Less Colors for Man Pages
export LESS_TERMCAP_mb=$'\E[01;31m' # begin blinking
export LESS_TERMCAP_md=$'\E[01;38;5;74m' # begin bold
export LESS_TERMCAP_me=$'\E[0m' # end mode
export LESS_TERMCAP_se=$'\E[0m' # end standout-mode
export LESS_TERMCAP_so=$'\E[38;5;016m\E[48;5;220m' # begin standout-mode - info box
export LESS_TERMCAP_ue=$'\E[0m' # end underline
export LESS_TERMCAP_us=$'\E[04;38;5;146m' # begin underline
Reload your config and try a man page search :
. ~/.bashrc && man ls
Fixed it. The problem is to do with the way that the screen $TERM handles italics. From the tmux FAQ:
vim displays reverse video instead of italics, while less displays italics
(or just regular text) instead of reverse. What's wrong?
This matches my problem exactly. The $PAGER used by man is less by default - basically, man uses less to show the contents of the manual pages. In my case, less wasn't highlighting text, just showing regular text.
The reason for this happening:
Screen's terminfo description lacks italics mode and has standout mode in its
place, but using the same escape sequence that urxvt uses for italics. This
means applications (like vim) looking for italics will not find it and might
turn to reverse in its place, while applications (like less) asking for
standout will end up with italics instead of reverse.
The solution is to make a new terminfo file for tmux, which lets it know that italics are supported. The solution's outlined in the (at time of writing) very, very bottom of the tmux FAQ.
After creating the new terminfo file, in tmux: C-b :source-file /absolute/path/to/.tmux.conf (from this SuperUser question) - this should make tmux reload the .tmux.conf file. However, this didn't work for me, and the changes only applied after restarting the tmux server (close all tmux sessions, then re-open them).
This thread is a few years old but is still the one that comes up as the best search result, so I'm answering with what finally worked for me. This is based off of tmux FAQ.
...but the instructions aren't completely clear on when or where to substitute the -256color string. I use gnome-terminal (v 3.16.2) with tmux, and this worked for me:
$ mkdir $HOME/.terminfo/
$ screen_terminfo="screen-256color"
$ infocmp "$screen_terminfo" | sed \
-e 's/^screen[^|]*|[^,]*,/screen-256color|screen with italics support,/' \
-e 's/%?%p1%t;3%/%?%p1%t;7%/' \
-e 's/smso=[^,]*,/smso=\\E[7m,/' \
-e 's/rmso=[^,]*,/rmso=\\E[27m,/' \
-e '$s/$/ sitm=\\E[3m, ritm=\\E[23m,/' > /tmp/screen.terminfo
$ tic /tmp/screen.terminfo
And tell tmux to use it in ~/.tmux.conf:
set -g default-terminal "screen-256color"
Note: I tried it once without the -256color and since that didn't work (still seeing italics instead of highlighting), I had to delete everything under the .terminfo dir (another dir called 's') before the infocmp would work.

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