• Debugging Your SAS Program
• Consulting Help
• Customizing Your SAS Session
• SAS Tips
• SAS Sample Library
• SAS Newsgroup
• WWW Sites
• FTP Server
• Types of SAS Files
• Additional Information

Debugging Your SAS Program

Debugging a program takes time and will probably require you to read sections of SAS documentation. SAS documentation is available online at http://support.sas.com/documentation/onlinedoc/sas9doc.html (SAS 9.1.3 in html or pdf format). Manuals of earlier versions of SAS products are available for checkout from the Help Desk, Stephens 201.

Here are some guidelines you can follow when debugging your SAS program.

1. Examine the .log file for error messages.
2. Look in the SAS documentation for the correct syntax.
3. Check for missing semicolons and mismatched quotes.
4. Print out part of the data set to be sure that you are reading the data into the data set correctly. The SAS commands

   proc print data=mydata (firstobs=20 obs=24);
   run;

   print out all variables starting with the twentieth observation and ending with the twenty-fourth observation.

5. By default, SAS assumes that the record length of an input record is no longer that 256 characters. If the record length is longer than 256, include the lrecl option in the infile statement.
6. If there are TABS in the data file, include the expandtabs option in the infile statement.
7. If the data file uses commas as the delimiter between values, include the dsd option in the infile statement.
8. If the data file uses another character, such as a semicolon, as the delimiter between values, include the delimiter=';' option in the infile statement.
9. If you have any missing values, read the SAS documentation to see how the procedure you want to use handles missing values. Sometimes an entire observation is eliminated from analysis if one of its variables contains a missing value.
10. If your program contains many lines of code or many loops, use comments to help debug the program. Comment out parts of the program and get subsections working correctly. The following lines comment out a do loop.

    /* do i = ...
    ...
    end; */

11. If your program contains many lines of code or many loops, output intermediate results with the SAS file and put statements. The following statements output the contents of amount to the file debug.sas.prog

    file 'debug.sas.prog';
    put @1 amount 5.1;
    put @1 'output from first loop';

12. If your program causes your terminal (workstation) to lock up, then login to anther workstation, rlogin to the original workstation, and kill the process that caused the lockup. Useful Unix commands are
    
    

    Command	Action
    finger yourID	to see where else you are logged in
    rlogin workstation-name	to access your previous workstation
    ps -a	to display your active processes and their PIDs
    kill PID	to kill your process with this PID number

    
    
13. If you are locking up the workstation, you are running out of memory. If you have created several large data sets, use proc datasets to delete any data sets you are no longer using. If you are locking up the workstation because your log file is too big, you might have to either save the .log file in /tmp or not create the .log file at all. Put these options in sasv9.cfg
    
    
14. Run a cpu-intensive SAS program in the background with the sas_batch command.
    
    Type: sas_batch sas_job
    
    You will see a message
    Job # xxx started. To cancel it, rlogin to workstation.ucs.louisiana.edu and type: kill xxx
    
    
15. When running a cpu-intensive job, also consider dividing the program into several smaller steps and saving intermediate results between steps to a file.
    
    For example, suppose that you are generating 5000 numbers for analysis. Write a macro that generates and saves one number using SAS file and put statements. Add a do loop to call that macro any number of times, say 500. Run the do loop program 10 times to generate 5000 numbers.
    
    
16. If you are reading a very large data file, you can conserve disk space (not cpu cycles) by having SAS read a compressed data file.
    
    First compress the file. zip bigfile results in bigfile.zip
    
    To use bigfile.zip as input to your SAS program, include the following lines in your program.
    
    filename compres pipe 'unzip -p bigfile.zip';
    data one;
    infile compres missover;
    input ...;
    additional SAS commands
    run;
    

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Consulting Help

Contact the SAS consultant for consulting help.

When a program has errors, it is necessary for the consultant to look at the SAS program, data file, and SAS log. To send prog1.sas, prog1.dat and prog1.log to the SAS consultant, type

mail sas < prog1.sas
mail sas < prog1.dat
mail sas < prog1.log

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Customizing Your SAS Session

You can create two files, sasv9.cfg and autoexec.sas, that allow you to customize your SAS session during initialization processing. Put these files in the same directory where your SAS programs are located. When you execute SAS, SAS process these two files, and then SAS runs your program.

sasv9.cfg

This file contains valid SAS system option settings and executes before autoexec.sas file. Examine /pkgs3/sas_9.1/sasv9.cfg to view an example of a configuration file. SAS executes configuration files in the following order: first the SAS default configuration file in /pkgs3/sas_9.1/, then sasv9.cfg in the home directory, then sasv9.cfg in the working directory. SAS uses the last value it encounters for the option.

1. If you want to display the listing file on your screen, include the line

   -linesize 80

2. If you do not want today's date printed on your listing file, add the line

   -nodate

3. If your output or log listings are large, you can redirect the files to /usr/tmp (temporary space). First create /usr/tmp/abc1234 directory.

   cd /usr/tmp
   mkdir /usr/tmp/abc1234

   Then include the following lines in sasv9.cfg

   -print /usr/tmp/abc1234/prog1.lst
   -log /usr/tmp/abc1234/prog1.log

4. If you do not want a SAS log file created when you run your SAS program, add the line

   -log /dev/null

Information on other SAS system options is discussed in SAS Languge Reference: Dictionary and SAS 9.1 Companion for UNIX Environments.

autoexec.sas

autoexec.sas executes after sasv9.cfg and before the SAS program. It contains valid SAS statements. Refer to SAS Languge Reference: Dictionary for a list of valid SAS statements. Create this file in your SAS directory. If you frequently use SAS data libraries, create autoexec.sas and include libname statements of frequently used SAS data libraries. For example, use a text editor to create a file called autoexec.sas that contains the line

libname in '/home/abc1234/sasdir';

Now you do not have to include the libname statement in your SAS programs that reference the SAS data library in.*

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SAS Tips

Create graph to display in Adobe Acrobat Reader on your computer

You can create a graph as a .pdf file, ftp the file to your own computer, view the graph using (free) Adobe Acrobat Reader, and print the graph on your own printer.

1. Include the following in your SAS program

   filename gsasfile '/home/abc1234/graph.pdf';
   goptions device=pdf gaccess=gsasfile gprotocol=''
   gsfmode=replace handshake=none rotate;

2. Run the SAS program and create the file graph.pdf in your home directory.
3. ftp the file to your PC.

   ftp ucs_workstation
   User: your_ucs_account
   Password: your_ucs_password
   ftp> binary
   ftp> get graph.pdf
   ftp> bye

4. View the graph.pdf file in Adobe Acrobat Reader. Print the graph.

Note: You can create a graphics file (jpg, cgm) that can be imported into other software programs (word processing programs, presentation software, etc). Check with the SAS consultant for the name of the device driver to use for a particular software program.

Infile Options

When using the infile command, you can specify options.

infile 'file_name' <options>;

See SAS 9.1.3 Language Reference: Dictionary for a complete list of options. Some of the more frequently used options are listed in the following table.

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SAS Sample Library

/pkgs3/sas_9.1/samples contains directories base, ets, graph, iml, or, qc, stat. These directories contain the SAS Sample Library for the various SAS products. Use these programs to examine examples of various SAS procedures. For example, suppose you want to use the SAS/BASE proc means procedure. Type cd /pkgs3/sas_9.1/samples/base and then type:

grep MEANS *.* | more

You will see a display on your screen of all files in the directory that contain the word 'MEANS'. Note: the programs are written in upper case. You see several references to 'MEANS' in the means.sas program. If you do not need to modify the means program then you can use the program in the samples library. Link to the program and run it.

ln -s /pkgs3/sas_9.1/samples/base/means.sas means.sas
sas means

means.log and means.lst are written to your working directory. If you want to modify the program, copy means.sas to your SAS directory.

cp /pkgs3/sas_9.1/samples/base/means.sas means.sas
sas means

Modify, run, and examine the SAS log and listing files. Refer to the documentation for proc means if you are unsure about the syntax.

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SAS Newsgroup

SAS-L has a FAQ (Frequently Asked Questions) and searchable archives.

You can also subscribe to comp.soft-sys.sas and read the latest SAS-L newsgroup postings.

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WWW Sites

The SAS Institute web site contains a great deal of information. In particular, SAS Customer Support Center includes various sources to help you solve problems. For example, you can search the entire support site, you can search SAS Notes (primary source used by the SAS Technical Support Consultants), and you can also view code samples.

Numerous other sites contain statistics and SAS information. To locate the most current information use a web search program such as Google.

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FTP Server

The SAS FTP server contains files of interest to SAS users such as technical information and sample programs.

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Types of SAS Files

Different types of SAS files serve different functions. SAS automatically assigns a certain extension to each file when it creates the file. The file extension determines the function as the following table shows.

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Additional Information

For additional information, contact the Help Desk,

Stephens Hall 201; 482-5516.