little wrapper around `vd --diff` to get diff's -U option, since vd doesn't have a "go to next difference" feature ( https://github.com/saulpw/visidata/issues/303 )

vddiff

#!/bin/bash

# Usage:
# $ vddiff -U4 before after -ftsv

# You can toggle between the before/after sheets with Ctrl-^
# If you keyboard layout makes that impossible to type, add an
# alternative binding to your ~/.visidatarc, e.g.
# bindkey("ø", "prev-sheet")

set -e -u

d=$(mktemp -td vddiff.XXXXXXXXXXX)
trap 'rm -rf "${d}"' EXIT

declare -i U=3
OPTIND=1; while getopts "U:" opt; do
    case "$opt" in
        U) U=$OPTARG;;
        *)
            echo "Unknown option" >&2
            exit 1
            ;;
    esac
done
shift $((OPTIND-1))

before="$1"
after="$2"
shift 2                         # send anything after the files to vd

test -e "${before}"
test -e "${after}"

skipheader () {
    tail -n+2 "$@"
}

{
    printf " "
    head -1 "${before}"
    diff -U"$U"                    \
         <(skipheader "${before}") \
         <(skipheader "${after}")  \
        | grep -ve ^@@ -e ^--- -e ^+++
} > "$d/diffout"

undiff () {
    local discard="$1"
    grep -v ^"${discard}" "$d/diffout" \
        | sed 's/^.//'
}
undiff + >"$d/before"
undiff - >"$d/after"

vd "$@" --diff "$d/before" "$d/after"