#! bash

# Useful bash functions. This is sourced by the environment file.
# These are available to scripts, but you shouldn't use them in scripts if you
# want them to be portable.


# Usage: pathremove /path/to/bin [PATH]
# Eg, to remove ~/bin from $PATH
#     pathremove ~/bin PATH
function pathremove {
	local IFS=':'
	local NEWPATH
	local DIR
	local PATHVARIABLE=${2:-PATH}
	for DIR in ${!PATHVARIABLE} ; do
		if [ "${DIR}" != "${1}" ] ; then
			NEWPATH="${NEWPATH:+${NEWPATH}:}${DIR}"
		fi
	done
	export ${PATHVARIABLE}="${NEWPATH}"
}

# Usage: pathprepend /path/to/bin [PATH]
# Eg, to prepend ~/bin to $PATH
#     pathprepend ~/bin PATH
function pathprepend {
	pathremove "${1}" "${2}"
	[ -d "${1}" ] || return
	local PATHVARIABLE="${2:-PATH}"
	export ${PATHVARIABLE}="${1}${!PATHVARIABLE:+:${!PATHVARIABLE}}"
}

# Usage: pathappend /path/to/bin [PATH]
# Eg, to append ~/bin to $PATH
#     pathappend ~/bin PATH
function pathappend {
	pathremove "${1}" "${2}"
	[ -d "${1}" ] || return
	local PATHVARIABLE=${2:-PATH}
	export $PATHVARIABLE="${!PATHVARIABLE:+${!PATHVARIABLE}:}${1}"
}

# Usage: ssource /path/to/shellscript
# Checks if the file exists before sourcing it
function ssource {
	[ -r "${1}" ] && source "${1}"
}

# Sets colours to be appropriate for a light on dark terminal
function darkterm {
	DARK=1
	source "${HOME}/.bash/colors"
}

# Sets the colours to be appropriate for a dark on light terminal
function lightterm {
	DARK=0
	source "${HOME}/.bash/colors"
}

# Usage: mcd somedir
# Creates the directory if it doesn't exist, and changes into it
function mcd {
	mkdir -p "${1}" &&
	cd "${1}"
}

# Usage: vimf somefile
# Does a recursive search of the current directory for somefile, then edits it
function vimf {
	find . -name "${1}" -exec vim '{}' +
}

# Sets the nice and ionice priorities for the current shell to the lowest values
function slowshell {
	ionice -c 3 -p $$
	renice -n 19 -p $$
}

# Usage: is_function something
# Check if a function exists
function is_function {
	declare -Ff "$1" > /dev/null
}

# Load local functions
ssource "${HOME}/.bash/functions_local"