Small utilities for working with bash

bash_aliases.sh

#!/bin/bash
# +-----------------+
# | Path management |
# +-----------------+

export ___ORIGINAL_PATH="${PATH}"

function get_path() {
    echo "Current path: ${PATH}"
}

function set_path() {
    export PATH="${1}"
    echo "New path: ${PATH}"
}

function reset_path() {
    set_path "${___ORIGINAL_PATH}"
}

function add_to_path() {
    set_path "${PATH}:`pwd`"
}

# +---------------------+
# | Directory bookmarks |
# +---------------------+

# !defined(name) test is based upon:
# http://unix.stackexchange.com/questions/56837/how-to-test-if-a-variable-is-defined-at-all-in-bash-prior-to-version-4-2-with-
if [ ! -n "${___BOOKMARKS+1}" ]; then
    export ___BOOKMARKS=()  
fi

___CURRENT=${CURRENT:-0}

function ___resolve_path() {
    echo "$( cd "$1" && pwd )"
}

function ___is_number() {
    [[ "$1" =~ ^-?[0-9]+$ ]] && return 0 || return 1
}

# Array operations are based upon:
# http://www.yourownlinux.com/2013/10/working-with-arrays-in-bash-scripting.html
function ___append_bookmark() { 
    if ___contains_bookmark "${1}"; then return -1; fi
    local LENGTH=${#___BOOKMARKS[@]}
    ___BOOKMARKS[$LENGTH]="${1}"
    ___fix_current
}

function ___remove_bookmark() {
    local idx=0
    for target in "${___BOOKMARKS[@]}"; do 
        if [ "${target}" == "${1}" ]; then
            ___BOOKMARKS=(${___BOOKMARKS[@]:0:$idx} ${___BOOKMARKS[@]:$(expr $idx + 1)})
            ___fix_current
            return 0;
        fi
        idx=$((idx+1))
    done
    return 1
}

function ___move_to_front() {
    ___remove_bookmark "${1}" || return -1
    ___BOOKMARKS=("$1" "{___BOOKMARKS[@]}")
}

function ___update_completion() {
    complete -W "${___BOOKMARKS[*]}" goto
}

# Update on loading (in case ___BOOKMARKS was set by a parent script)
___update_completion

function ___contains_bookmark() {
    for target in "${___BOOKMARKS[@]}"; do 
        if [ "${target}" == "${1}" ]; then return 0; fi
    done
    return 1
}

function ___index_of_bookmark() {
    local i=0
    for target in "${___BOOKMARKS[@]}"; do 
        if [ "${target}" == "${1}" ]; then
            echo "${i}"
            return 0
        fi
        i=$((i+1))
    done
    return 1
}

function ___fix_current() {
    local COUNT=${#___BOOKMARKS[@]}
    local MAX_INDEX=$((COUNT - 1))
    if [ ${___CURRENT} -gt ${MAX_INDEX} ]; then
        ___CURRENT=${MAX_INDEX}
    fi
    if [ ${___CURRENT} -lt 0 ]; then
        ___CURRENT=0
    fi
}

# List all bookmarks
function bookmarks() {
    local i=0
    for target in "${___BOOKMARKS[@]}"; do
        local marker=" "
        if [ ${i} == ${___CURRENT} ]; then marker="*"; fi
        echo "${marker} Bookmark ${i}: ${target}"
        i=$((i+1))     
    done
}

# Create a new bookmark
function mark() {
    local DIR=`___resolve_path "${1:-.}"`
    if [ "${DIR}" == "" ]; then return -1; fi
    ___append_bookmark "${DIR}" && \
    echo "New bookmark: ${DIR}" || \
    echo "Already present: ${DIR}"
    ___update_completion
}

# Remove a bookmark
function unmark() {
    local dir_or_num="${1:-}"
    if ___is_number "${dir_or_num}"; then
        local DIR="${___BOOKMARKS[${dir_or_num}]}"
    else
        local DIR=`___resolve_path "${dir_or_num}"`
    fi
    if [ "${DIR}" == "" ]; then return -1; fi
    ___remove_bookmark "${DIR}" && \
    echo "Removed bookmark: ${DIR}" || \
    echo "No bookmark found: ${DIR}"
    ___update_completion
}

# Goto a bookmark
function goto() {
    local dir_or_num="${1:-}"
    if ___is_number "${dir_or_num}"; then
        local DIR="${___BOOKMARKS[${dir_or_num}]}"
    else
        local DIR=`___resolve_path "${dir_or_num}"`
    fi
    if [ "${DIR}" == "" ]; then return -1; fi
    # ___move_to_front "${DIR}"
    ___CURRENT=`___index_of_bookmark "${DIR}"`
    cd "${DIR}"
    ___update_completion
}


# Navigate backward
function back() {
    ___CURRENT=$((___CURRENT - 1))
    ___fix_current
    goto ${___CURRENT}
}

# Navigate forward
function forward() {
    ___CURRENT=$((___CURRENT + 1))
    ___fix_current
    goto ${___CURRENT}
}

# +--------------+
# | UI utilities |
# +--------------+

function print_separator() {
    # Term window detection is based upon:
    # http://stackoverflow.com/questions/263890/how-do-i-find-the-width-height-of-a-terminal-window
    local COLS="`tput cols`"
    local TIMES="${1:-3}"
    
    # Char repetition is based upon:
    # http://stackoverflow.com/questions/5349718/how-can-i-repeat-a-character-in-bash
    for i in `eval "echo {1..$TIMES}"`; do
        printf '=%.0s' `eval "echo {1..$COLS}"`
        echo ""
    done   
}