On my linux pc I can find the example libraries and installed libraries by the library manager under Arduino-1.8.8\libraries, but on the iMac I can't find them. I suppose they are hidden, but nevertheless I don't know where to find them.
Please some help.
Sketchbook: {sketchbook folder}/libraries. The sketchbook folder location can be found (or changed) at File > Preferences > Sketchbook location:. This is the location of libraries installed via Library Manager (Sketch > Include Library > Manage Libraries...) or Sketch > Include Library > Add .ZIP Library. You should also manually install libraries to that location.
IDE: {Arduino IDE install folder}/libraries. This is for the libraries included with the Arduino IDE installation. You should never install libraries to that folder because they will be lost when you update to a new IDE version.
Core: This is dependent on the current selection in Tools > Board. Location will depend on if you're using a hardware core bundled with the IDE, installed via Boards Manager, or manually installed to {sketchbook folder}/hardware. The best way to find it is to do:
File > Examples > SPI > BarometricPressureSensor
(or any other SPI library example sketch)
Sketch > Show Sketch Folder - this will open the SPI/examples/BarometricPressureSensor folder inside of the current hardware core's libraries folder
To find any library do this:
File > Examples > open any example from the library you want to find
Sketch > Show Sketch Folder - this will open the example folder inside of the library folder.
To further clarify what pert was saying, assuming you’ve done a default installation of the Arduino IDE on the Mac here are the pertinent libraries.
Accessing the files within the Arduino.app, right-click on the app and select "Show Package Contents. You will then see:
/Applications/Arduino.app/Contents/Java/libraries. ← common libraries like LiquidCrystal
/Applications/Arduino.app/Contents/Java/hardware/arduino/avr/libraries ← hardware core libraries like EEPROM
Please be aware packages are read only.
Again assuming a default installation of the Arduino IDE on Mac:
/Users/<user_name>/Documents/Arduino/libraries ← if lower case the libraries are read only
or -
/Users/<user_name>/Documents/Arduino/Libraries. ← if uppercase the libraries are read/write
Note: I’ve been using Arduino for so long, I always set to “Libraries”, it’s possible the uppecase/lowercase
situation no longer applies, but to be safe…