makes an alias of the last commandline, escaping properly & allowing for review (I have not reviewed this so use at your own risk)

alias-last.sh

# This function avoids having to:
# - vim into the right file
# - write out the alias syntax
# - quote a commandline's embedded quotes, which can get rather gnarly
# - reformat from line-squashing
# - add negative numbers (will auto-convert)
# TODO: Bug with aliasing THIS line: sed 's/\ -/ \\\n\t\-/g'
function aliaslast() {
    #APPEND_LOCATION=~/.bp_local
    if [[ -f ~/dotfiles/frags/bp_scratch ]]; then
        APPEND_LOCATION=~/dotfiles/frags/bp_scratch
    else
        APPEND_LOCATION=~/.bashrc
    fi


    if [[ $1 == -d ]]; then local DBUG=1; shift; fi
    if [[ $1 == --no-append ]]; then local NO_APPEND=1; shift; fi

    ############################
    # Get the line from history
    if [[ $# == 0 ]]; then
        subshell_adjusted_num=-1
    elif [[ $# == 1 ]]; then
        # Add a dash (for negative number) if not already present
        if [[ ${1:0:1} == "-" ]]; then # take it as-is
            subshell_adjusted_num="$1"
        else # add a dash
            subshell_adjusted_num="-${1}"
        fi
    else 
        error "Too many args."
    fi
    # SAN for shorthand
    SAN=$subshell_adjusted_num

    # Debug printing:
    if [[ $DBUG == 1 ]]; then 
        echo -e 'fc of subshell:\n'"$(fc -l $(( $SAN - 5 )) $SAN)"
        echo "SAN: $SAN"
    fi

    # Get & clean the cmdline
    rawline="$(fc -ln $SAN $SAN)"
    lastline="$(echo "$rawline" |
        sed 's/^[[:space:]]*//g' |
        sed 's/[[:space:]]*$//g')"

    echo -e "${YELO}To be aliased:${NC} '$lastline'"

    # To see if there is a context where alternative-implementations would be more thorough
    lastline2=$(history | tail -2 | head -1 | sed -r 's/^[ \t]*[0-9]*[ \t]+([^ \t].*$)/\1/')
    lastline3=$(fc -ln "$(( ${1:0} - 2 ))" | sed '$ d' | sed 's/^[[:space:]]*//g' )
    echo -e "$GREY"
        echo "ALTERNATIVES:"
        [[ $DBUG == 1 ]] && echo "rawline is: $rawline"
        echo "lastline2 is: $lastline2"
        echo "lastline3 is: $lastline3"
    echo -e "$NC"

    # Get name of alias from the user, then make it in current-environment
    printf "${YELO}Enter a name for the [alias]:${NC} "
    read ALIASNAME 
    alias "${ALIASNAME}"="$lastline"

    # Save it to a file for future sessions
    if [[ "$NO_APPEND" == 1 ]]; then
        echo -e "${ORANGE}TEMPORARY: Not added to bashrc.${NC}"
    else
        echo -e ${ELECTRIC_BLUE}
        alias "$ALIASNAME" | tee -a $APPEND_LOCATION
        echo -e ${NC}
    fi
}
alias al="aliaslast"
alias aln="aliaslast --no-append"
# ^ for when you want a quick-n-dirty alias for something you'll probably run a lot
# - all 3 are basically the same for for-loops
# - the fc-way works for quote-lines (ones that dont collapse naturally with semi-colons)
# ... but history chokes on that
# WORKS FOR:
# 1. single lines
# 2. multiline quotes
# 3. multiline loops, cases
# 4. neg-ref
# 5. pos-ref
# BUG: for aliasing: manpath | tr ':' '\n' | nl, \n triggers a newline