Multiple path environment variable setup lines with bash

You can do:

export PATH="A"
export PATH="$PATH:B"
export PATH="$PATH:C"

Each subsequent line appends onto the previously defined path. This is generally a good habit, as it avoids trashing the existing path. If you want the new component to take precedence, swap the order:

export PATH="A"
export PATH="B:$PATH"
export PATH="C:$PATH"

Alternatively, you might be able to do:

export PATH=A:\
B:\ 
C

where \ marks a line continuation. Haven't tested this method.

You can extend lines in bash using a backslash at the end of a line like this:

export PATH=/path/A:\
/path/B:\
/path/C

Please note that the absence of white space is important here.