A tutorial introduction to Swarm: Building demos

Finding and unpacking programs

Sample Objective C models are available here (ftp://ftp.swarm.org/pub/swarm/apps/objc/sdg/swarmapps-2.1.1.tar.gz).

Sample Java models are available here (ftp://ftp.swarm.org/pub/swarm/apps/java).

An easy way to grab files

An easy way to grab files from the command line is to use the wget program. We'll get and unpack the Objective C demo applications and the Java version of heatbugs, for starters:

        $ cd /arc
        $ wget ftp://ftp.swarm.org/pub/swarm/apps/objc/sdg/swarmapps-2.1.1.tar.gz
        $ wget ftp://ftp.swarm.org/pub/swarm/apps/java/sdg/jheatbugs-2.1.tar.gz

To unpack, use the GNU tar (http://www.gnu.org/software/tar) program.

        $ cd /src
        $ tar xzf /arc/swarmapps-2.1.1.tar.gz 
        $ tar zxf /arc/jheatbugs-2.1.tar.gz

GNU tar vs. other tar programs

Other tar programs, such as found on Solaris, don't support the -z option. With these tar programs you may need to connect gzip output to tar via a stream:

        $ cd /src
        $ gzip -dc /arc/swarmapps-2.1.1.tar.gz | tar xf -

Archives are usually made to include a directory structure, so that when they are unpacked, a subdirectory having of the same name as the archive is created (minus the .tar.gz).

Table 2. GNU Tar options

Option	Purpose
-x	Extract
-z	(De)compress
-f	Use file argument
--help	Get help