djcev.com

#!/bin/sh
#
#  Copyright (c) 2015-2021, Cameron Vanderzanden. Available under the
#  terms of the 2-clause BSD license. Please see the file "LICENSE" in
#  the root dir of this repository for more information.
#
#- xvt.sh 2015/01/14 cev, last updated 2021/12/07.
## Usage: xvt.sh [-hnV] [-d directory] [-t timeout] [-u urgency]
## 
##     Detect the CWD of the currently selected window and run a new
##     terminal window in the same CWD. Requires herbstluftwm.
## 
##       -d     Change to <directory> instead of checking focused win's CWD
##       -h     Show help
##       -n     Announce detected parameters via dbus notification
##       -t     Notification timeout (notify-send -t)
##       -u     Notification urgency (notify-send -u)
##       -V     Print version info
## 
#  This'll break if you run a shell within a shell. It (should) only detect
#  the outside shell. Might be fixed by altering the logic to check PPID.

[ -x $HOME/.local/bin/cev_print.sh ] && . $HOME/.local/bin/cev_print.sh

self="${0##*'/'}"
cwd=""
notify=""
os="$(uname -s)"
terminal="/usr/local/bin/alacritty"
timeout=1000
urgency="low"

freebsd_cleanup() {
    if [ -n "$envfile" -a -e "$envfile" ]; then rm $envfile; fi
    if [ -n "$fdfile" -a -e "$fdfile" ]; then rm $fdfile; fi
}

while getopts "d:hnt:u:V?" option; do
    case $option in
        d) cwd="$OPTARG" ;;
        h) print_help && exit ;;
        n) notify="Y" ;;
        t) timeout="$OPTARG" ;;
        u) urgency="$OPTARG" ;;
        V) print_version && exit ;;
        "?") print_help && exit ;;
    esac
    shift $((OPTIND - 1))
done

# read the focused window ID. sh does the hex to dec conversion.
# requires that the window manager set _NET_ACTIVE_WINDOW
id=$(xprop -root | grep '_NET_ACTIVE_WINDOW(WINDOW):' | cut -d'#' -f 2-)
if [ -n "$id" ]; then
    id=$(($id))
fi

if [ -n "$cwd" -o -z "$id" ]; then
    pid="$$" && exe="$SHELL"
elif [ "$os" = "FreeBSD" ]; then
    # store the env of every process whose env contains WINDOWID=$id,
    # then look for the first process where COMM matches $SHELL.
    trap freebsd_cleanup EXIT
    envfile=$(mktemp ${TMPDIR:-/tmp}/${self}.1.XXXXXXXX)
    procstat -aeh | grep "WINDOWID=$id" 2>/dev/null 1>$envfile
    while read epid ecomm eenv; do
        if [ "$(which $ecomm)" = "$SHELL" ]; then
            # this is probably the shell running within the focused window.
            # read its file descriptor info, pull out cwd, then break.
            fdfile=$(mktemp ${TMPDIR:-/tmp}/${self}.2.XXXXXXXX)
            procstat -fh $epid 2>/dev/null 1>$fdfile
            while read fpid fcomm ffd ft fv fflags fref foffset fpro fname; do
                if [ "$ffd" = "cwd" ]; then
                    pid="$epid" && exe="$ecomm" && cwd="$fname"
                fi
            done < $fdfile
            rm $fdfile
            break
        fi
    done < $envfile
    rm $envfile
elif [ "$os" = "Linux" ]; then
    # grab the PID of every process whose environment contains WINDOWID=id
    pids=$(grep "WID=$id" /proc/[0-9]*/environ 2>/dev/null | tr -d '[:alpha:]/')
    # iterate; assume the first process whose exe matches the user's shell
    # is the currently active shell in the window, then read and store its
    # current working directory.
    for xpid in $pids; do
        if [ "/proc/$xpid/exe" -ef "$SHELL" ]; then
            # assume the program we pass cwd to will dereference the symlink
            pid="$xpid" && exe="$SHELL" && cwd="/proc/$xpid/cwd"
            break
        fi
    done
fi

# If we found a directory above, run your terminal in that dir.
if [ -z "$cwd" ]; then pid="$$" && exe="$SHELL" && cwd="$HOME"; fi
print_self
printf "%brefpid %s, exe %s, cwd %s%b\n" "$_norm" "$pid" "$exe" "$cwd" "$_clear"
if [ -n "$notify" ]; then
    notify-send -t "$timeout" -u "$urgency" -a "$self" "$cwd"
fi
cd "$cwd"
exec $terminal $*