z/z.sh

# Copyright (c) 2009 rupa deadwyler under the WTFPL license

# maintains a jump-list of the directories you actually use
#
# INSTALL:
#     * put something like this in your .bashrc/.zshrc:
#         . /path/to/z.sh
#     * cd around for a while to build up the db
#     * PROFIT!!
#     * optionally:
#         set $_Z_CMD in .bashrc/.zshrc to change the command (default z).
#         set $_Z_DATA in .bashrc/.zshrc to change the datafile (default ~/.z).
#         set $_Z_NO_RESOLVE_SYMLINKS to prevent symlink resolution.
#         set $_Z_NO_PROMPT_COMMAND if you're handling PROMPT_COMMAND yourself.
#         set $_Z_EXCLUDE_DIRS to an array of directories to exclude.
#
# USE:
#     * z foo     # cd to most frecent dir matching foo
#     * z foo bar # cd to most frecent dir matching foo and bar
#     * z -r foo  # cd to highest ranked dir matching foo
#     * z -t foo  # cd to most recently accessed dir matching foo
#     * z -l foo  # list matches instead of cd
#     * z -c foo  # restrict matches to subdirs of $PWD

[ -d "${_Z_DATA:-$HOME/.z}" ] && {
    echo "ERROR: z.sh's datafile (${_Z_DATA:-$HOME/.z}) is a directory."
}

_z() {

    local datafile="${_Z_DATA:-$HOME/.z}"

    # bail if we don't own ~/.z (we're another user but our ENV is still set)
    [ -f "$datafile" -a ! -O "$datafile" ] && return

    local exclude;

    # tab completion
    if [ "$1" = "--complete" ]; then
        while read line; do
            [ -d "${line%%\|*}" ] && echo $line
            for exclude in "${_Z_EXCLUDE_DIRS[@]}"; do
                [ "${line%%\|*}" = "$exclude" ] && continue
            done
        done < "$datafile" | awk -v q="$2" -F"|" '
            BEGIN {
                if( q == tolower(q) ) imatch = 1
                q = substr(q, 3)
                gsub(" ", ".*", q)
            }
            {
                if( imatch ) {
                    if( tolower($1) ~ tolower(q) ) print $1
                } else if( $1 ~ q ) print $1
            }
        ' 2>/dev/null

    else
        # list/go
        while [ "$1" ]; do case "$1" in
            --) while [ "$1" ]; do shift; local fnd="$fnd${fnd:+ }$1";done;;
            -*) local opt=${1:1}; while [ "$opt" ]; do case ${opt:0:1} in
                    c) local fnd="^$PWD $fnd";;
                    h) echo "${_Z_CMD:-z} [-chlrtx] args" >&2; return;;
                    x) sed -i -e "\:^${PWD}|.*:d" "$datafile";;
                    l) local list=1;;
                    r) local typ="rank";;
                    t) local typ="recent";;
                esac; opt=${opt:1}; done;;
             *) local fnd="$fnd${fnd:+ }$1";;
        esac; local last=$1; shift; done
        [ "$fnd" -a "$fnd" != "^$PWD " ] || local list=1

        # if we hit enter on a completion just go there
        case "$last" in
            # completions will always start with /
            /*) [ -z "$list" -a -d "$last" ] && cd "$last" && return;;
        esac

        # no file yet
        [ -f "$datafile" ] || return

        local cd
        cd="$(while read line; do
            [ -d "${line%%\|*}" ] && echo $line
            for exclude in "${_Z_EXCLUDE_DIRS[@]}"; do
                [ "${line%%\|*}" = "$exclude" ] && continue
            done
        done < "$datafile" | awk -v t="$(date +%s)" -v list="$list" -v typ="$typ" -v q="$fnd" -F"|" '
            function frecent(rank, time) {
                # relate frequency and time
                dx = t - time
                if( dx < 3600 ) return rank * 4
                if( dx < 86400 ) return rank * 2
                if( dx < 604800 ) return rank / 2
                return rank / 4
            }
            function output(files, out, common) {
                # list or return the desired directory
                if( list ) {
                    cmd = "sort -n >&2"
                    for( x in files ) {
                        if( files[x] ) printf "%-10s %s\n", files[x], x | cmd
                    }
                    if( common ) {
                        printf "%-10s %s\n", "common:", common > "/dev/stderr"
                    }
                } else {
                    if( common ) out = common
                    print out
                }
            }
            function common(matches) {
                # find the common root of a list of matches, if it exists
                for( x in matches ) {
                    if( matches[x] && (!short || length(x) < length(short)) ) {
                        short = x
                    }
                }
                if( short == "/" ) return
                # use a copy to escape special characters, as we want to return
                # the original. yeah, this escaping is awful.
                clean_short = short
                gsub(/[\(\)\[\]\|]/, "\\\\&", clean_short)
                for( x in matches ) if( matches[x] && x !~ clean_short ) return
                return short
            }
            BEGIN {
                gsub(" ", ".*", q)
                hi_rank = ihi_rank = -9999999999
            }
            {
                if( typ == "rank" ) {
                    rank = $2
                } else if( typ == "recent" ) {
                    rank = $3 - t
                } else rank = frecent($2, $3)
                if( $1 ~ q ) {
                    matches[$1] = rank
                } else if( tolower($1) ~ tolower(q) ) imatches[$1] = rank
                if( matches[$1] && matches[$1] > hi_rank ) {
                    best_match = $1
                    hi_rank = matches[$1]
                } else if( imatches[$1] && imatches[$1] > ihi_rank ) {
                    ibest_match = $1
                    ihi_rank = imatches[$1]
                }
            }
            END {
                # prefer case sensitive
                if( best_match ) {
                    output(matches, best_match, common(matches))
                } else if( ibest_match ) {
                    output(imatches, ibest_match, common(imatches))
                }
            }
        ')"
        [ $? -gt 0 ] && return
        [ "$cd" ] && cd "$cd"
    fi
}

alias ${_Z_CMD:-z}='_z 2>&1'

[ "$_Z_NO_RESOLVE_SYMLINKS" ] || _Z_RESOLVE_SYMLINKS="-P"

if compctl >/dev/null 2>&1; then
    # zsh
    [ "$_Z_NO_PROMPT_COMMAND" ] || {
        # populate directory list, avoid clobbering any other precmds.
        if [ "$_Z_NO_RESOLVE_SYMLINKS" ]; then
            _z_precmd() {
                /usr/local/bin/_z_prompt_command "${PWD:a}"
            }
        else
            _z_precmd() {
                /usr/local/bin/_z_prompt_command "${PWD:A}"
            }
        fi
        [[ -n "${precmd_functions[(r)_z_precmd]}" ]] || {
            precmd_functions[$(($#precmd_functions+1))]=_z_precmd
        }
    }
    _z_zsh_tab_completion() {
        # tab completion
        local compl
        read -l compl
        reply=(${(f)"$(_z --complete "$compl")"})
    }
    compctl -U -K _z_zsh_tab_completion _z
elif complete >/dev/null 2>&1; then
    # bash
    # tab completion
    complete -o filenames -C '_z --complete "$COMP_LINE"' ${_Z_CMD:-z}
    [ "$_Z_NO_PROMPT_COMMAND" ] || {
        # populate directory list. avoid clobbering other PROMPT_COMMANDs.
        grep "_z_prompt_command" <<< "$PROMPT_COMMAND" >/dev/null || {
            PROMPT_COMMAND="$PROMPT_COMMAND"$'\n''/usr/local/bin/_z_prompt_command "$(pwd '$_Z_RESOLVE_SYMLINKS' 2>/dev/null)";'
        }
    }
fi

# we can unset these as they are only used during setup
unset -v _Z_NO_PROMPT_COMMAND _Z_NO_RESOLVE_SYMLINKS _Z_RESOLVE_SYMLINKS