ampac — Execute AMPAC input files.


The ampac shell command is the primary means of executing AMPAC input files. The ampac utility runs in the background (but can also run in the foreground using the -fg option) and can run a batch of AMPAC jobs sequentially. A simple summary of the each AMPAC job is written to screen just prior to executing to that job. To execute large number of files, mampac may be preferable.

AMPAC 9 no longer supports version control. (In previous versions, AMPAC would avoid overwritting previous results files by appending a version number to each of the result files.) Care should be taken in running jobs to not overwrite previous output files associated with the input file.


ampac [-fg] [-b] [-mem] [-s] [-nproc=#|all|most|half] [filename(s)]
ampac help



Run job in foreground [default run in background].


Batch mode. Job is non-interactively in the foreground.


Turn on memory profiling (see below for details).


Output to screen instead of file.


Specifies the number of processors to use--equivalent to NPROC.


One or more AMPAC input files of type *.dat. Multiple filenames can be entered separated by spaces. UNIX file globbing (for example, using * as a wildcard) is also supported.

Memory Profiling

The memory profiling option is a new feature that allows users to determine the amount of memory used by a particular job. As AMPAC is being used to study larger and larger systems, it is important for users to be able to know how much memory a job requires so as to estimate how big of a system can be run on their computer. In many cases, top or ps is sufficient for this purpose, however, memory profiling provides a much more detailed report and so can provide information that these other commands cannot.

Using -mem will cause the AMPAC job to be run in the background while the script repeatedly polls the job using the ps -el command once per second until it finishes. The results for filename.dat will appear in a seperate file named filename.mem in plain text format. The maximum memory used by the job is also reported to the screen.

There are a few things to keep in mind in using this feature. The memory usage should be considered approximate and may vary slightly each time the job is run because we are only looking at snapshots. The results should only be compared to jobs running under the same operating system, since operating systems vary in how they report memory. Jobs that complete in a few seconds or less will likely produce no results and report zero memory consumption, since it may finish before there is a chance to test for memory usage.

Interactive Use

If no file is specified then ampac will interactively prompt the user for a file. In place of an input file, the user may also enter:

h or help

Brings up help documentation in the form of a text file.

q or quit

Exits interactive mode.


Output from AMPAC is written to the screen. For example, output from ampac test01.dat test02.dat will be similar to:

Submitting AMPAC 9.0 Data file:  test1.dat
Running in Temporary Directory:  amp3792
AMPAC: /home/semo/Ampac/program/ampac.exe

Tue Jun 10 15:35:11 CDT 2008

Submitting AMPAC 9.0 Data file:  test2.dat
Running in Temporary Directory:  amp3792
AMPAC: /home/semo/Ampac/program/ampac.exe

Tue Jun 10 15:35:12 CDT 2008
0.2u 0.6s 0:02 40%

See also:

Chapter 5, Presenting Input to the Program