Go · · · Combining `cd` and `ls` commands into one

gistfile1.sh

##
# Simple utility to change directory and list files in one step. If no
# arguments are provided, it just lists the files in the current
# directory. This allows the script to be used as both `cd` and `ls`.
#
# Go to directory and list files:
# `go /home/philosoraptor/thoughts -Ahl`
#
# List files in current directory:
# `go -Ahl`
#
# @author  L. Daniel Nordstrom <[email protected]>
# @version 0.1.0
# @license MPL 2.0
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
##

# Prints a header with a dashed line (or any other character).
# 
# Parameters
#   $1 - Header text
#   $2 - Character used to generate line (default: "-")
printHeader() {
  if [ -n "$1" ]; then
    local line=""
    local text="$1"
    local character="$2"

    [ -z $character ] && character="-"

    for (( i=0; i<${#text}; ++i )); do line="$line$character"; done

    printf "%s\n%s" "$text" "$line"
  fi
}

# Prints a banner with dashed lines (or any other character).
# 
# Parameters
#   $1 - Banner text
#   $2 - Character used to generate lines (default: "-")
printBanner() {
  if [ -n "$1" ]; then
    local line=""
    local text="$1"
    local character="$2"

    [ -z $character ] && character="-"

    text="$character $text $character"

    for (( i=0; i<${#text}; ++i )); do line="$line$character"; done

    printf "%s\n%s\n%s" "$line" "$text" "$line"
  fi
}

ls="ls"
directory=""

# Get any optional directory and `ls` flags.
while [ $# -gt 0 ]; do
  case "$1" in

    # Argument is a flag.
    -*) ls="$ls $1" ;;

    # Argument is (hopefully) a directory.
    *) directory="$1" ;;

  esac
  shift
done

# Run commands.
if [ -n "$directory" ]; then
  # Directory provided: change to it and list files, unless directory
  # is invalid (change "&&" to ";" to list files even if `cd` fails).
  # Quotation marks are needed for `cd` to allow spaces in paths.
  eval "cd \"$directory\"" && \
    printf "\n" && \
    printHeader "$PWD" && \
    printf "\n" && \
    eval "$ls" && \
    printf "\n"
else
  # Directory not provided: list files with any optional flags.
  printf "\n" && \
    printHeader "$PWD" && \
    printf "\n" && \
    eval "$ls" && \
    printf "\n"
fi