get_cols () {
    # Usage: get_cols [file_name] [column_num]
    column_list=""
    for column_num in $@; do
	[ -r $column_num ] && continue

	[ $column_num -lt '0' ] && column_num="(NF + 1 $column_num )" #Negative indices like python's array[-1]

	[ -z $column_list ] && column_num="\$$column_num" || column_num=",\$$column_num" # Place commas appropriately.

	column_list="$column_list$column_num"
    done
    unset column_num

    # Is the first parameter a file?
    if [ -r $1 ]; then
	awk "{print $column_list}" $1
    else
	awk "{print $column_list}"
    fi
    unset column_list
}

note() {
    if [ $# -eq 0 ]; then
        (ym && exec $EDITOR $HOME/notes/$(git rev-parse --abbrev-ref HEAD)) ;
    else
        $EDITOR $HOME/notes/"$*" ;
    fi
}

list_notes() {
    ls -c $HOME/notes/ | grep "$*"
}

function get_shas_that_touched() {
    git log --oneline --reverse "$@" | get_col 1
}

function echo_hash_if_exp_found_in_filename_diff() {
    [ ! -z "$(git diff $1~1 $1 -- $2 | cat | grep $3)" ] && echo $1
}

function get_shas_that_touched_with_grep() {
    get_shas_that_touched $1 | xargs -I the_hash sh -c 'echo_hash_if_exp_found_in_filename_diff the_hash $1 $2'
}

function show_interdiffs_matching_grep() {
    get_shas_that_touched_with_grep $1 $2 | xargs -I hash sh -c 'git diff hash~1 hash -- $1'
}

function find_all_ssh_agent_sockets() {
    find /tmp -type s -name agent.\* 2> /dev/null | grep '/tmp/ssh-.*/agent.*'
}

function set_ssh_agent_socket() {
    export SSH_AUTH_SOCK=$(find_all_ssh_agent_sockets | tail -n 1 | awk -F: '{print $1}')
}

# Create a new directory and enter it
function mkd() {
    mkdir -p "$@" && cd "$@"
}

# Determine size of a file or total size of a directory
function fs() {
    if du -b /dev/null > /dev/null 2>&1; then
	local arg=-sbh
    else
	local arg=-sh
    fi
    if [[ -n "$@" ]]; then
	du $arg -- "$@"
    else
	du $arg .[^.]* *
    fi
}

# Use Git’s colored diff when available
hash git &>/dev/null
if [ $? -eq 0 ]; then
    function diff() {
	git diff --no-index --color-words "$@"
    }
fi

# Create a data URL from a file
function dataurl() {
    local mimeType=$(file -b --mime-type "$1")
    if [[ $mimeType == text/* ]]; then
	mimeType="${mimeType};charset=utf-8"
    fi
    echo "data:${mimeType};base64,$(openssl base64 -in "$1" | tr -d '\n')"
}

# Start an HTTP server from a directory, optionally specifying the port
function server() {
    local port="${1:-8000}"
    sleep 1 && open "http://localhost:${port}/" &
	# Set the default Content-Type to `text/plain` instead of `application/octet-stream`
	# And serve everything as UTF-8 (although not technically correct, this doesn’t break anything for binary files)
    python -c $'import SimpleHTTPServer;\nmap = SimpleHTTPServer.SimpleHTTPRequestHandler.extensions_map;\nmap[""] = "text/plain";\nfor key, value in map.items():\n\tmap[key] = value + ";charset=UTF-8";\nSimpleHTTPServer.test();' "$port"
}

# Start a PHP server from a directory, optionally specifying the port
# (Requires PHP 5.4.0+.)
function phpserver() {
    local port="${1:-4000}"
    local ip=$(ipconfig getifaddr en1)
    sleep 1 && open "http://${ip}:${port}/" &
    php -S "${ip}:${port}"
}

# Compare original and gzipped file size
function gz() {
    local origsize=$(wc -c < "$1")
    local gzipsize=$(gzip -c "$1" | wc -c)
    local ratio=$(echo "$gzipsize * 100/ $origsize" | bc -l)
    printf "orig: %d bytes\n" "$origsize"
    printf "gzip: %d bytes (%2.2f%%)\n" "$gzipsize" "$ratio"
}

# Test if HTTP compression (RFC 2616 + SDCH) is enabled for a given URL.
# Send a fake UA string for sites that sniff it instead of using the Accept-Encoding header. (Looking at you, ajax.googleapis.com!)
function httpcompression() {
    encoding="$(curl -LIs -H 'User-Agent: Mozilla/5 Gecko' -H 'Accept-Encoding: gzip,deflate,compress,sdch' "$1" | grep '^Content-Encoding:')" && echo "$1 is encoded using ${encoding#* }" || echo "$1 is not using any encoding"
}

# Syntax-highlight JSON strings or files
# Usage: `json '{"foo":42}'` or `echo '{"foo":42}' | json`
function json() {
    if [ -t 0 ]; then # argument
	python -mjson.tool <<< "$*" | pygmentize -l javascript
    else # pipe
	python -mjson.tool | pygmentize -l javascript
    fi
}

# All the dig info
function digga() {
    dig +nocmd "$1" any +multiline +noall +answer
}

# Escape UTF-8 characters into their 3-byte format
function escape() {
    printf "\\\x%s" $(printf "$@" | xxd -p -c1 -u)
    echo # newline
}

# Decode \x{ABCD}-style Unicode escape sequences
function unidecode() {
    perl -e "binmode(STDOUT, ':utf8'); print \"$@\""
    echo # newline
}

# Get a character’s Unicode code point
function codepoint() {
    perl -e "use utf8; print sprintf('U+%04X', ord(\"$@\"))"
    echo # newline
}

# Add note to Notes.app (OS X 10.8)
# Usage: `note 'foo'` or `echo 'foo' | note`
function note() {
    local text
    if [ -t 0 ]; then # argument
	text="$1"
    else # pipe
	text=$(cat)
    fi
    body=$(echo "$text" | sed -E 's|$|<br>|g')
    osascript >/dev/null <<EOF
tell application "Notes"
	tell account "iCloud"
		tell folder "Notes"
			make new note with properties {name:"$text", body:"$body"}
		end tell
	end tell
end tell
EOF
}

# Add reminder to Reminders.app (OS X 10.8)
# Usage: `remind 'foo'` or `echo 'foo' | remind`
function remind() {
    local text
    if [ -t 0 ]; then
	text="$1" # argument
    else
	text=$(cat) # pipe
    fi
    osascript >/dev/null <<EOF
tell application "Reminders"
	tell the default list
		make new reminder with properties {name:"$text"}
	end tell
end tell
EOF
}

# Manually remove a downloaded app or file from the quarantine
function unquarantine() {
    for attribute in com.apple.metadata:kMDItemDownloadedDate com.apple.metadata:kMDItemWhereFroms com.apple.quarantine; do
	xattr -r -d "$attribute" "$@"
    done
}