topic Re: adding "return code" to a macro in SAS Programming

adding "return code" to a macro

desertsp — Thu, 12 Jul 2018 18:02:27 GMT

I have a macro which, when executed, sets a global variable (named &SearchResult) to a 1 or 0. I would instead prefer the macro itself evaluate to 1 or 0, without having to set a global variable.

BTW - this will be used for program control. The macro is checking whether a log file contains the word SUCCESS, and if so, the main program is allowed to continue processing.

Here is what I have now:

%macro CheckFileForString(FilenameAndPath=,
                          SearchString=);

   %global SearchResult; 
   %let SearchResult = 0; /* default unless the string is found */

      /* scan FilenameAndPath for SearchString */
    filename finp ("&FilenameAndPath");
	data result;
	  infile finp filename = _filepath  truncover;
	  input a_line $1000.; /* read first 1000 bytes of each line */
	  if find(a_line,"&SearchString")  then do;  	    
            call symput('SearchResult',1);  /* set the return code  */
		                                end;
	run;	
%mend;

%macro main_program;
   /* search a log file for the string SUCCESS */
 %CheckFileForString(FilenameAndPath=C:\TEMP\LOGFILE.LOG,
                     SearchString= SUCCESS);

 %IF &SearchResult = 1 %THEN 

   %PUT NOTE: Processing can continue;

 %ELSE 
   %PUT ERROR: The log file does not contain the word SUCCESS. Processing must halt;
%mend;

  %main_program;

Here is how I would prefer to setup %main_program. %CheckFileForString needs to evaluate to a 1 or 0, but I'm not sure how to accomplish that.

%macro main_program;

   /* check if a log file contains the word SUCCESS */
 %IF %CheckFileForString(FilenameAndPath=C:\TEMP\LCM_PYLOG.LOG,
                         SearchString= SUCCESS) = 1 %THEN 

   %PUT NOTE: Processing can continue;

 %ELSE 
   %PUT ERROR: The log file does not contain the word SUCCESS. Processing must halt;
%mend;

  %main_program;

Re: adding "return code" to a macro

EEng — Thu, 12 Jul 2018 18:56:32 GMT

You don't want to use SYSCC?

You can add this in the beginning of your code

%Let syscc=0; ** Operating Environment Condition Code **;

And after each macro, you can add this into your code:

if &syscc>0 then your log message.

From SAS notes (Usage Note 35553)

SYSCC is a read/write automatic macro variable that enables you to reset the job condition code and to recover from conditions that prevent subsequent steps from running. The values for SYSCC are:

0 is no errors no warnings
4 is warnings
> 4 is an error occurred

Re: adding "return code" to a macro

desertsp — Thu, 12 Jul 2018 19:43:30 GMT

I was not aware of SYSCC - it sounds very useful for trapping unexpected errors. Thank you!

If you don't mind, could you please demonstrate how I would incorporate this logic? If I'm not mistaken, my %CheckFileForString macro does not generate an "error" per se, even if the string isn't found.

Or are you simply suggesting that I replace my own &SearchResult with &SYSCC?

Re: adding "return code" to a macro

ballardw — Thu, 12 Jul 2018 22:36:38 GMT

Here is one way to expose a single value without a global macro variable:

%macro dummy (value);
   %if &value=10 %then %let result=1;
   %else %let result=0;
   &result
%mend;

%macro main_program;
   /* search a log file for the string SUCCESS */
 
 %IF %dummy(10) = 1 %THEN 
   %PUT NOTE: Processing can continue;
 %ELSE 
   %PUT ERROR: The value is not 10. Processing must halt;
%mend;

%main_program;

The local macro variable result exposed as a single statement without any ; to end the statement.

Test other values with something like:

%put %dummy(5);

You might want to include a LRECL parameter on our INFILE statement.

Re: adding "return code" to a macro

andreas_lds — Fri, 13 Jul 2018 04:20:01 GMT

Macros returning values can't use data-steps or procs, only macro-code is allowed. In the following example sashelp.class is not printed, but the code is returned to the calling macro.

%macro dummy;
   %local z;
   %let z = 100;
  
   proc print data=sashelp.class;
   run;

   &z.

%mend;

%macro testbox;
   %local result;
   %let result = %dummy;
   %put -----------;
   %put &result.;
   %put -----------;
%mend;

%testbox;

Re: adding "return code" to a macro

FreelanceReinh — Fri, 13 Jul 2018 08:21:56 GMT

So, you may want to combine what @andreas_lds and @ballardw have suggested:

Avoid SAS code in macro CheckFileForString.
Let the macro code end with a (local) macro variable reference.

The result, a (preliminary) function-style version of CheckFileForString, could look something like this:

%macro CheckFileForString(FilenameAndPath=,
                          SearchString=);
%local SearchResult filrf rc fid c;
%let SearchResult = 0; /* default unless the string is found */
%let filrf=srcf;
%let rc=%sysfunc(filename(filrf, &FilenameAndPath));
%let fid=%sysfunc(fopen(&filrf));
%if &fid > 0 %then %do;
  %do %while(%sysfunc(fread(&fid))=0);
    %let rc=%sysfunc(fget(&fid, c, 1000)); /* read first 1000 bytes of each line */
    %if %index(%superq(c), &SearchString) %then %let SearchResult=1; /* set the return code */
  %end;
  %let rc=%sysfunc(fclose(&fid));
%end;
%let rc=%sysfunc(filename(filrf));
&SearchResult
%mend CheckFileForString;

Re: adding "return code" to a macro

desertsp — Fri, 13 Jul 2018 14:46:27 GMT

Thank you - I see you also improved how the macro works with the file, which I appreciate!

Re: adding "return code" to a macro

desertsp — Fri, 13 Jul 2018 14:52:08 GMT

Thank you! I don't have much experience working with infile (usually, I work with existing SAS datasets)

and I appreciate you pointing out my omission of LRECL.

Re: adding "return code" to a macro

desertsp — Fri, 13 Jul 2018 14:58:41 GMT

I definitely need to learn more about when macros resolve to "text" and when they resolve to "executetable code". Your example helps with that understanding. Thanks!