npm

libx11

Core X11 protocol client library for X.Org display server

brewmacoslinux
Try with needOr install directly
Source

About

X.Org: Core X11 protocol client library

Commands

libx11

Examples

Check if libx11 is installed and view library information$ pkg-config --list-all | grep libx11
Get libx11 version and compiler flags for development$ pkg-config --cflags --libs x11
Verify libx11 library files are available in system paths$ ldconfig -p | grep libX11