If you see a Command not found error, ensure you have run the module load intel command first. With both the compiler module and the the MPI libraries loaded, you can now compiler your trap. This command will show no output when run, but if you run ls after it completes, you will see a new executable file appear: trap-mpichv2.
This page provies an example using Intel compilers. For a more comprehensive overview of all the compiler commands and options available, refer to our software page. For instance, the entry:. BAK , and so forth for y.
This technique works because make reads the dependency list twice, once as part of its initial reading of the entire makefile , and again as it processes target dependencies. In each pass through the list, it performs macro expansion. Since the dynamic macros aren't defined in the initial reading, unless references to them are delayed until the second pass, they are expanded to null strings.
Notice that make only evaluates the target-name portion of a target entry in the first pass. A delayed macro reference as a target name produces incorrect results. The makefile :. Here again, a delayed reference to a make macro produces incorrect results. There is no transitive closure for suffix rules.
If you had a suffix rule for building, say, a. Y file from a. X file, and another for building a. Z file from a. Y file, make would not combine their rules to build a. X file. You must specify the intermediate steps as targets, although their entries can have null rules:.
In this example trans. Z is built from trans. Y if it exists. Without the appearance of trans. Y as a target entry, make might fail with a "don't know how to build" error, since there would be no dependency file to use. The target entry for trans. Y guarantees that make will attempt to build it when it is out of date or missing. Since no rule is supplied in the makefile , make will use the appropriate implicit rule, which in this case would be the.
Y rule. If trans. X exists or can be retrieved from SCCS , make rebuilds both trans. Y and trans. Z as needed. Although make supplies you with a number of useful suffix rules, you can also add new ones of your own. However, pattern-matching rules are to be preferred when adding new implicit rules see "Pattern-Matching Rules: An Alternative to Suffix Rules ". Because different kinds of computers do not speak each others' machine languages, a compiled program will only work on the platform it was designed for.
Despite this drawback, compiled programs are faster than those that must be run through an interpreter. Also, it is often possible to recompile the program so that it will run on different platforms. In an interpreted program, on the other hand, the source code typically is the program. Programs of this type often known as scripts require an interpreter, which parses the commands in the program and then executes them.
Some interpreters, such as the Unix shells sh , csh , ksh , etc. The advantage of a script is that it is very portable. Any computer that has the appropriate interpreter installed may run the program more or less unchanged. This is a disadvantage as well, because the program will not run at all if the interpreter is not available.
In general, interpreted programs are slower than compiled programs, but are easier to debug and revise. Other examples of interpreted languages include JavaScript and Python. But, with the development of just-in-time compilation , that gap is shrinking.
Most programming languages can have both compiled and interpreted implementations — the language itself is not necessarily compiled or interpreted. Python, for example, can be executed as either a compiled program or as an interpreted language in interactive mode. On the other hand, most command line tools, CLIs, and shells can theoretically be classified as interpreted languages.
Programs that are compiled into native machine code tend to be faster than interpreted code. This is because the process of translating code at run time adds to the overhead, and can cause the program to be slower overall.
Interpreted languages tend to be more flexible, and often offer features like dynamic typing and smaller program size. Also, because interpreters execute the source program code themselves, the code itself is platform independent. If this article was helpful, tweet it.
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