how to add a directory to path fish code example
Example 1: fish shell add to path
set -Ua fish_user_paths /path/to/add
# fish_user_paths is equivilent to PATH
# -U make variable univeral
# -a append variable
Example 2: fish add to path
set -gx PATH /opt/qt/Tools/QtCreator/bin /opt/qt/5.0.0/gcc_64/bin $PATH