What are scripts and GMT

In general scripts are files that contain a list of commands to be successively executed. Shell scripts are lists of shell commands and gmt scripts are lists of gmt commands. As a normal user, you may not know nor care about the difference between gmt and shell scripts except that gmt must be installed in order for those particular commands to work; otherwise gmt has been written with enough intelligence that they look and act the same.

Purists insist that only sh should be used for scripts. Purists have the time and inclination to sit around and discover all the syntax differences and idiosyncracies of different shells. I'd rather spend my time getting work done. It is the opinion of this author that one should script in the shell one uses. Since most people at CERI use tcsh or csh, this seminar is exclusive to those shells.

Note: it is also possible to script on a pc running dos using a things called batch files. I don't know why you would want to do this since dos is a (brain) dead language.

Thus if you use the man page for something like foreach or if there will be several sections that give the syntax of the different shells. Pay attention to the csh sections and ignore the others. You can also man csh and get all kinds of gory details.

GMT is an acronym for Generic Mapping Tools developed and maintained by Paul Wessel and Walter Smith at the University of Hawaii and NOAA respectively. It is one of the most annoying programs I couldn't live without. I primarily use it to make maps, but have seen it used for all kinds of things that it wasn't designed for. Lots of people use it so there are lots of wheels you need not reinvent. It is different from applications you might be familiar with in that there is nothing to click on or start up. Rather it is just a bunch of commands (more or less) that you run.

In most cases your output will be postscript format. The same format suitable for printing to the printer, viewing with ghostscript, or porting to Adobe.

On rare occasions, you may have to start from scratch. By far the best method is to steal and modify someone else's script.

The GMT homepage is: gmt.soest.hawaii.edu.