The University of Illinois released the UNIX version of Mosaic into the public domain, so we obtained it from here
https://archives.library.illinois.edu/erec/University%20Archives/0705012/Unix/source/
We used Linux Ubuntu 18.04. Mosaic was written in the C programming language and the UNIX version uses the X11 (and Motif) as the windowing system. To install these libraries on Ubuntu Linux 18.04 do
sudo apt-get install libxt-dev libmotif-dev libxmu-headers libxmu-dev libxpm-dev
The original build system included 'make' files for several UNIX systems and later GNU automake was added. We added a build based on Qt because it provides an IDE with a built in debugger. To install Qt on linux
sudo apt-get install qt5-default qtcreator
The source code assumes the existence of the file 'config.h' at root, genereated by GNU automake. This file includes several pre-processor macros but is not needed for the Qt build, and can be generated with
touch config.h
The main Qt project file Mosaic.pro is located at root and it has the following contents
TEMPLATE = subdirs
SUBDIRS = libwww2 libXmx libhtmlw libnut src
which lists 4 subdirectories with libraries and the directory 'src', where the main program is located. To build, do at a command prompt at the root directory
/usr/bin/qmake -r
make
Mosaic uses 'libwww', the original World Wide Web C library written by its inventor, Tim Berners-Lee. The source included an implementation of the function 'getline'
static int getline(char *s, int n, FILE *f)
that was standardized in POSIX.1-2008, so we can just comment this definition. I also includes a declaration of
extern char *sys_errlist[];
that in recent Linux must be changed to
extern const char *const sys_errlist[];
This library includes the pre-standard C header <varargs.h>
and the function definition
static int PSprintf(format, va_alist)
The header must be changed to <stdarg.h>
and the function to
static int PSprintf(char *format, ...)