diffdir

#!/bin/bash
# Author: Gokberk Cinbis, 2022
set -e

function __increment_argi__() # just increment argi variable
{
    argi=$((argi+1))
}


function __decrement_argi__() # just decrement argi variable
{
    argi=$((argi-1)) 
}


function __print_help__ () 
{
    echo "diffdir [--nogit] [--vimdiff] <path1> <path2>"
    echo "Compare two directories recursively, with handy options."
    echo ""
    echo "ARGUMENTS"
    echo "--nogit          Discard all results involving .git"
    echo "--vim,-vimdiff   vimdiff resulting files (prompts before vimdiff)."
    # HIDDEN ARGUMENT: --debug
    exit 1
}

function __main__()
{
    local narg=$#
    local i_=$((narg-1))
    local path1="${!i_}" # second from the last 
    local path2="${!narg}" # the last argument

    if [ $narg -lt 2 ]
    then
        __print_help__
    fi

    findargs=()
    grepargs=()
    debug=0
    nogit=0
    vimdiff_=0

    argi=0 # argument reading index
    for (( argi=1; argi<=$((narg-2)); argi++ )); do
        if [ "${!argi}" == '--nogit' ]; then  
            nogit=1
        elif [ "${!argi}" == '--help' ]; then  
            __print_help__
        elif [ "${!argi}" == '--debug' ]; then  
            debug=1
        elif [[ "${!argi}" == '--vim' ]]; then  
            vimdiff_=1
        elif [[ "${!argi}" == '--vimdiff' ]]; then  
            vimdiff_=1
        #elif [[ "${!argi}" == '-e' ]]; then  
        #    __increment_argi__
        #    if [ $argi -eq $narg ]; then
        #        __print_help__ # we'd read <regexp> as <ext> incorrectly
        #    fi
        #    # doesnt work: findargs+=('-name' "\"*.${!argi}\"")
        #    findargs+=('-name' "*.${!argi}")
        else
            command echo "Unrecognized argument: ${!argi}"
            __print_help__
        fi
    done

    # check if folders exist
    [ ! -d "$path1" ] && echo "$path1 does not exist or not a directory." && exit 2
    [ ! -d "$path2" ] && echo "$path2 does not exist or not a directory." && exit 2

    outfile=$(mktemp)
    set +e # otherwise pipeline fails
    if [ $nogit -eq 1 ]; then
        command diff --recursive --brief --exclude=".git" "$path1" "$path2" > "$outfile"
    else
        command diff --recursive --brief "$path1" "$path2" > "$outfile"
    fi
    set -e
    if [ $vimdiff_ -eq 1 ]; then
        outfile_diffs=$(mktemp)
        outfile_onlyins=$(mktemp)
        tmp=$(mktemp)
        tmp2=$(mktemp)
        # https://stackoverflow.com/questions/5410757/how-to-delete-from-a-text-file-all-lines-that-contain-a-specific-string
        command sed '/^Only in/d' "$outfile" > "$outfile_diffs"
        command sed '/^Files /d' "$outfile" > "$outfile_onlyins"

        # differing file pairs
        command sed 's/^Files /vimdiff /g' "$outfile_diffs" > "$tmp"
        command sed 's/ and / /g' "$tmp" > "$tmp2"
        command sed 's/ differ$//g' "$tmp2" > "$tmp"
        command echo "### Differing file pairs"
        command cat "$tmp"

        # Simply print one-sided files
        command echo ""
        command echo "### Files that appear only in one of the two directories (not opened in vimdiff)"
        command cat "$outfile_onlyins"

        # Create the final script: add "set -e" so that :cquit in vim stops the comparisons
        # todo: errtrace / catch :cquit exit and notify
        command echo "!/bin/bash" > "$tmp2"
        command echo "set -e" >> "$tmp2"
        command cat "$tmp" >> "$tmp2"
        command chmod 700 "$tmp2"

        if [ $debug -eq 1 ]; then
            command echo "==== FINAL SCRIPT TO BE EXECUTED ====" 
            command cat "$tmp2" 
        fi

        # vimdiff time
        command echo ""
        command read -p "Do you want to vimdiff each differing pair? (*** Use :cquit to stop diffs ***) [y/n]: " -n 1 -r # ask before as it is quite annoying when the # is very large
        if [[ $REPLY =~ ^[Yy]$ ]]
        then
            "$tmp2" # run the script
        else
            command echo ""
            command echo "Cancelled."
        fi

        # clean up 
        command rm -f "$outfile_onlyins" "$outfile_diffs" "$tmp" "$tmp2"
    else
        # simply print diff output
        command cat "$outfile"
    fi
    # clean up
    command rm -f "$outfile"

}

if [ $# -lt 2 ] # avoid segfault on macos
then
    __print_help__
fi

# ok with multiple quoted arguments
__main__ "$@"
exit 0