This macro checks for the existence of a `.sashdat` file in a CASLIB. It uses the CAS action `table.fileinfo` executed via `dosubl()` to retrieve the list of files. To optimize performance during multiple calls, the result is cached in a local WORK table (defined by `outprefix`). The macro returns 1 if the file exists, 0 otherwise.
Data Analysis
Type : EXTERNE
Data comes from the CAS server's system information (list of files in a CASLIB) retrieved via `PROC CAS`.
1 Code Block
PROC CAS Data
Explanation :
This conditional block checks if the cache exists. If not, it uses `dosubl` to execute `PROC CAS` and the `table.fileinfo` action to list the library's files, then a DATA step to filter only `.sashdat` files and create the cache table.
This conditional block checks if the cache exists. If not, it uses `dosubl` to execute `PROC CAS` and the `table.fileinfo` action to list the library's files, then a DATA step to filter only `.sashdat` files and create the cache table.
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| 1 | %IF %sysfunc(exist(&outprefix._&lib)) ne 1 %THEN %DO; |
| 2 | %let rc=%sysfunc(dosubl(%nrstr( |
| 3 | /* Read in table list (once per &lib per session) */ |
| 4 | PROC CAS; |
| 5 | TABLE.fileinfo RESULT=source_list /caslib="&lib"; |
| 6 | val=findtable(source_list); |
| 7 | saveresult val dataout=&outprefix._&lib; |
| 8 | QUIT; |
| 9 | /* Only keep name, without file extension */ |
| 10 | DATA &outprefix._&lib; |
| 11 | SET &outprefix._&lib(where=(Name like '%.sashdat') keep=Name); |
| 12 | Name=upcase(scan(Name,1,'.')); |
| 13 | RUN; |
| 14 | ))); |
| 15 | %END; |
2 Code Block
SAS Functions
Explanation :
This block queries the local cache table via `open` and `fetch` functions to check if the requested table name (`&ds`) is present, and returns the boolean result (1 or 0).
This block queries the local cache table via `open` and `fetch` functions to check if the requested table name (`&ds`) is present, and returns the boolean result (1 or 0).
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| 1 | /* Scan table for hdat existence */ |
| 2 | %let dsid=%sysfunc(open(&outprefix._&lib(where=(name="&ds")))); |
| 3 | %syscall SET(dsid); |
| 4 | %let rc = %sysfunc(fetch(&dsid)); |
| 5 | %let rc = %sysfunc(close(&dsid)); |
| 6 | |
| 7 | /* Return result */ |
| 8 | %IF "%trim(&name)"="%trim(&ds)" %THEN 1; |
| 9 | %ELSE 0; |
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Copyright Info : Mathieu Blauw
