Subhash Mantha
SAS Developer
subhashmantha@gmail.com
Audit trail
 Important in the following fields
 Clinical Trials
 Financial Companies
 Product Development
 Answers four important questions
 When
 Why
 How
 Who
Some of the parameters used for
Trail Capturing
 Date
 Time
 Who ran the program
 Run time of the program
Methods for capturing a trail
 SAS Logs
 Excel Files
 XML files
 SAS Datasets
 CSV/Text Files
SAS Way of capturing a trail
 Datasets
 Append
 Modify
 Recreate
 External files
 Append
 Recreate
Trail by datasets
 Data step
 Set
 Modify
 Proc step
 Append
Trail by external files
 Data step
 File (recreate)
 File with mod option (append)
 Proc step
 Proc export (Recreate /add new sheets to an existing
file)
 ODS CSVALL
Writing to external files
 Data step
 Proc step
 SAS File functions
SAS File functions
 Filename: Assigns a file reference in a data step
 Fexist: Checks if a file exists.
 Fopen : opens the file and creates a file handler
 Fclose : Closes the file that has been opened using the
file handler
 Fput : Writes the information to the file data buffer
 Fwrite : Writes data from file data buffer to the actual
file
Appending information to the
bottom of a file
Data step:
Data _null_;
File <fileref> <file options> mod;
Set somedsname;
Put fields we want;
Run;
File functions:
Data _null_;
Rc_open=filename(‘fileref’, “full file name along with path”);
if rc_open=0 and fexist(‘fileref’) then do;
fid=fopen(‘fileref’ , ’a’);
putrc=fput(fid,<string to be written to the file>);
writerc=fwrite(fid);
closerc=fclose(fid);
End;
Run;
Advantages of using file functions
 Verify if the file exists
 Check if the file is in use
 Wait until the file is available to use
 Catch exceptions if data write to a file failed
 Help work around user locks
Concurrent access of datasets
 Found in multi user systems
 Several people trying to access the same file
 Others might have a file in read mode while somebody
else is trying to update the file
 Methods to address concurrent access :
 “Assume” That it never happens as in a single user
system
 Try to resolve the lock
Code
%macro update_audit_file (name_of_program=,
campaign_channel=,
result_of_run=&syscc._&sysrc._&sysmsg,
name_of_audit_file=);
%local user date_of_run ;
%let user=%sysget(USERNAME);
%let date_of_run=%sysfunc(putn(%sysfunc(datetime()),datetime18.));
%let filerf=update;
proc sql noprint;
select distinct scan(xpath,-1,'\') into :files separated by '|' from sashelp.vextfl
where index(xpath,'.sas')>0;
quit;
%let rc=%sysfunc(filename(filerf,"&name_of_audit_file"));
%put rc=&rc;
%if %sysfunc(fexist(&filerf)) %then %do;
%let open_rc=%sysfunc(fopen(&filerf,a));
%put &open_rc=;
%do %while (&open_rc <= 0 );
%let rc_sleep=%sysfunc(sleep(10));
%put The file being updated is open please close it;
%put SAS will try to update it in 10 seconds;
%let open_rc=%sysfunc(fopen(&filerf,a));
%end;
Code Continued….
%if &open_rc > 0 %then %do;
%let log=%sysfunc(getoption(altlog)); %let log_file=%sysfunc(scan(%str(&log),-1,'\'));
%let list=%sysfunc(getoption(altprint)); %let list_file=%sysfunc(scan(%str(&list),-1,'\'));
%let path=%sysfunc(getoption(sasinitialfolder));
%let
put_rc=%sysfunc(fput(&open_rc,%str(&user,&date_of_run,&name_of_campaign,&campaign_channel,&path,&result_
of_run,&log_file,&list_file,&files)));
%let write_rc=%sysfunc(fwrite(&open_rc));
%let close_rc=%sysfunc(fclose(&open_rc));
%end;
%put &open_rc &close_rc;
%end;
%else %do;
%put the file &filerf does not exist;
%put creating file &name_of_audit_file;
data _null_;
file "&name_of_audit_file";
put 'user,dateofrun,name_of_campaign,campaign_channel,path,result_of_run,log_file,list_file,files';
%put %sysfunc(sysmsg());
%end;
%mend update_audit_file;
 References
 SAS on-line documentation in Release 9.1.3
 Using SAS Functions in Data Steps, Yue Ye, The R.W. Johnson
Pharmaceutical Research Institute, Raritan, NJ Yong Lin, The
Cancer Institute of New Jersey, New Brunswick, NJ
 Acknowledgements
 Vitaly Feldman, SAS Institute Inc.