Once a program is built,
it is often appropriate to install it in another
directory for public use.
You use the Install method
to arrange for a program, or any other file,
to be copied into a destination directory:
env = Environment()
hello = env.Program('hello.c')
env.Install('/usr/bin', hello)
Note, however, that installing a file is
still considered a type of file "build."
This is important when you remember that
the default behavior of SCons is
to build files in or below the current directory.
If, as in the example above,
you are installing files in a directory
outside of the top-level SConstruct file's directory tree,
you must specify that directory
(or a higher directory, such as /)
for it to install anything there:
%scons -Qcc -o hello.o -c hello.c cc -o hello hello.o %scons -Q /usr/binInstall file: "hello" as "/usr/bin/hello"
It can, however, be cumbersome to remember
(and type) the specific destination directory
in which the program (or other file)
should be installed. A call to Default can be used to
add the directory to the list of default targets,
removing the need to type it,
but sometimes you don't want to install on every build.
This is an area where the Alias
function comes in handy,
allowing you, for example,
to create a pseudo-target named install
that can expand to the specified destination directory:
env = Environment()
hello = env.Program('hello.c')
env.Install('/usr/bin', hello)
env.Alias('install', '/usr/bin')
This then yields the more natural ability to install the program in its destination as a separate invocation, as follows:
%scons -Qcc -o hello.o -c hello.c cc -o hello hello.o %scons -Q installInstall file: "hello" as "/usr/bin/hello"
You can install multiple files into a directory
simply by calling the Install function multiple times:
env = Environment()
hello = env.Program('hello.c')
goodbye = env.Program('goodbye.c')
env.Install('/usr/bin', hello)
env.Install('/usr/bin', goodbye)
env.Alias('install', '/usr/bin')
Or, more succinctly, listing the multiple input files in a list (just like you can do with any other builder):
env = Environment()
hello = env.Program('hello.c')
goodbye = env.Program('goodbye.c')
env.Install('/usr/bin', [hello, goodbye])
env.Alias('install', '/usr/bin')
Either of these two examples yields:
% scons -Q install
cc -o goodbye.o -c goodbye.c
cc -o goodbye goodbye.o
Install file: "goodbye" as "/usr/bin/goodbye"
cc -o hello.o -c hello.c
cc -o hello hello.o
Install file: "hello" as "/usr/bin/hello"