# Generate a random string
#
# example: pwd=$(ynh_string_random 8)
#
# usage: ynh_string_random [length]
# | arg: length - the string length to generate (default: 24)
ynh_string_random() {
    dd if=/dev/urandom bs=1 count=200 2> /dev/null \
      | tr -c -d 'A-Za-z0-9' \
      | sed -n 's/\(.\{'"${1:-24}"'\}\).*/\1/p'
}

# Substitute/replace a string (or expression) by another in a file
#
# usage: ynh_replace_string match_string replace_string target_file
# | arg: match_string - String to be searched and replaced in the file
# | arg: replace_string - String that will replace matches
# | arg: target_file - File in which the string will be replaced.
#
# As this helper is based on sed command, regular expressions and
# references to sub-expressions can be used
# (see sed manual page for more information)
ynh_replace_string () {
	local delimit=@
	local match_string=$1
	local replace_string=$2
	local workfile=$3

        # Escape any backslash to preserve them as simple backslash.
        match_string=${match_string//\\/"\\\\"}
        replace_string=${replace_string//\\/"\\\\"}

        # Escape the & character, who has a special function in sed.
        match_string=${match_string//&/"\&"}
        replace_string=${replace_string//&/"\&"}

	# Escape the delimiter if it's in the string.
	match_string=${match_string//${delimit}/"\\${delimit}"}
	replace_string=${replace_string//${delimit}/"\\${delimit}"}

	sudo sed --in-place "s${delimit}${match_string}${delimit}${replace_string}${delimit}g" "$workfile"
}