Using SAS Macro to pipe a list of filenames from a Windows directory

Question

I am trying to amend the macro below to accept a macro parameter as the \'location\' argument for a dir command. However I cannot get it to resolve correctly due to the nes

Answer 1

Here's another way of achieving the same result without needing to use a PIPE.

%macro get_filenames(location);
filename _dir_ "%bquote(&location.)";
data filenames(keep=memname);
  handle=dopen( '_dir_' );
  if handle > 0 then do;
    count=dnum(handle);
    do i=1 to count;
      memname=dread(handle,i);
      output filenames;
    end;
  end;
  rc=dclose(handle);
run;
filename _dir_ clear;
%mend;

%get_filenames(C:\temp\);           
%get_filenames(C:\temp\with space);
%get_filenames(%bquote(C:\temp\with'singlequote));

Answer 2

Make the following several changes and your code will work.

%macro get_filenames(location);  %*--(1)--*;
   filename pipedir pipe "dir ""%unquote(&location)"" /b" lrecl=32767; %*--(2)--*;
   data filenames;
     infile pipedir truncover;
     input filename $char1000.;
     put filename=;
   run;
   filename pipedir clear;  %*--(3)--*;
%mend;

%get_filenames(d:\)          
%get_filenames(d:\your dir)  %*--(4)--*;

(1) End the %macro statement with a semi-colon;

(2) Surround the macro variable resolution with doubled-up double quotes and %unquote;

(3) Release the file handle by clearing it; and

(4) Don't single quote your input parameter. macro quote instead, if necessary.

Answer 3

it works for me if i call the original macro this way

%get_filenames(""C:\Program Files"")

of course i had to add the semicolon at the end of the %macro statement.

if your directory contains a comma, bad things happen. to fix, use the %str() macro

 %get_filenames(%str(C:\temp\comma, fail)) 

Answer 4

Based on the last sample on this page, instead of the filename statement, try

%let filrf=pipedir;
%let rc=%sysfunc(filename(filrf,%bquote(dir "&location" /b),pipe));

and call the macro without using quotes:

%get_filenames(c:\temp\with spaces);

I also tried macro quoting, but couldn't get it to work.

Answer 5

Here's one that unscrambles the order of quoting and unquoting:

%let command =%unquote(%str(%')dir "&baseDir.data\*txt"%str(%'));

filename datain pipe &command;

where macro variable basedir can contain spaces and so can the filenames. This combination of %unquote and %str(%') is a frequently occuring macro idiom.

"what if I have single quote in my dir?"

Handling this situation requires a macro quoting function, such as %bquote(); Continuing the example above, this:

%let command =%unquote(%str(%')dir "%bquote(&baseDir.data\*txt)"%str(%'));

should do it.

To avoid infinite iterations of this kind of question, look at Ian Whitlock's paper, A Serious Look at Macro Quoting, which is available here;

There are (many) others, but this is the most widely cited. A little note: anything by Ian Whitlock is probably worthwhile. He writes clearly and his understanding of SAS issues is awesome.

Answer 6

Here's a pure macro code version. It also allows you to specify that you only want to know about files (and not folders) and lets you specify a basic filter. It returns the list of files in a delimited format but you can easily insert these into a dataset using SQL insert if you wanted to (example included but not tested - no SAS access atm). It can be called from anywhere - within another macro, a dataset, an sql statement... wherever. Just add these two macros to your macro autocall library and you're right to go.

There are 2 macros below. The %isdir macro is required by the %file_list macro. The macros are a bit larger and more complex than the above but they are MUCH more flexible. Plus they provide error checking.

/******************************************************************************
** PROGRAM:  ISDIR.SAS
**
** DESCRIPTION: DETERMINES IF THE SPECIFIED PATH EXISTS OR NOT.
**              RETURNS: 0 IF THE PATH DOES NOT EXIST OR COULD NOT BE OPENED.
**                       1 IF THE PATH EXISTS AND CAN BE OPENED.
**
** PARAMETERS: iPath: THE FULL PATH TO EXAMINE.  NOTE THAT / AND \ ARE TREATED
**                    THE SAME SO &SASDIR/COMMON/MACROS IS THE SAME AS
**                    &SASDIR\COMMON\MACROS.
**
******************************************************************************/

%macro isDir(iPath=,iQuiet=1);
  %local result dname;

  %let result = 0;

  %if %sysfunc(filename(dname,&iPath)) eq 0 %then %do;
    %if %sysfunc(dopen(&dname)) %then %do;
      %let result = 1;
    %end;
    %else %if not &iQuiet %then %do;
      %put ERROR: ISDIR: %sysfunc(sysmsg());
    %end;
  %end;
  %else %if not &iQuiet %then %do;
    %put ERROR: ISDIR: %sysfunc(sysmsg());
  %end;

  &result

%mend;

%put %isDir(iPath=&sasdir/common/macros);
%put %isDir(iPath=&sasdir/kxjfdkebnefe);
%put %isDir(iPath=&sasdir/kxjfdkebnefe, iQuiet=0);
%put %isDir(iPath=c:\temp);

/******************************************************************************
** PROGRAM:  FILE_LIST.SAS
**
** DESCRIPTION: RETURNS THE LIST OF FILES IN A DIRECTORY SEPERATED BY THE
**              SPECIFIED DELIMITER. RETURNS AN EMPTY STRING IF THE THE 
**              DIRECTORY CAN'T BE READ OR DOES NOT EXIST.
**
** PARAMETERS: iPath      : THE FULL PATH TO EXAMINE.  NOTE THAT / AND \ ARE 
**                          TREATED THE SAME SO &SASDIR/COMMON/MACROS IS THE 
**                          SAME AS &SASDIR\COMMON\MACROS. WORKS WITH BOTH UNIX 
**                          AND WINDOWS.
**             iFilter    : SPECIFY A BASIC FILTER TO THE FILENAMES, NO REGULAR 
**                          EXPRESSIONS OR WILDCARDS.
**             iFiles_only: 0=RETURN FILES AND FOLDERS
**                          1=RETURN FILES ONLY.
**             iDelimiter : SPECIFY THE DELIMITER TO SEPERATE THE RESULTS BY.
******************************************************************************/
/*
** TODO: DOESNT CATER FOR MACRO CHARS IN FILENAMES. FIX SOMETIME.
** TODO: IMPROVE THE FILTER. JUST A SIMPLE IF STATEMENT AT THE MOMENT.
*/
%macro file_list(iPath=, iFilter=, iFiles_only=0, iDelimiter=|);
  %local result did dname cnt num_members filename;

  %let result=;

  %if %sysfunc(filename(dname,&iPath)) eq 0 %then %do;

    %let did = %sysfunc(dopen(&dname));
    %let num_members = %sysfunc(dnum(&did));

    %do cnt=1 %to &num_members;
      %let filename = %sysfunc(dread(&did,&cnt));
      %if "&filename" ne "" %then %do;
        %if &iFiles_only %then %do;
          %if not %isDir(iPath=&iPath/&filename) %then %do;
            %if "&iFilter" ne "" %then %do;
              %if %index(%lowcase(&filename),%lowcase(&iFilter)) %then %do;
                %let result = &result%str(&iDelimiter)&filename;
              %end;
            %end;
            %else %do;
              %let result = &result%str(&iDelimiter)&filename;
            %end;
          %end;
        %end;
        %else %do;
          %if "&iFilter" ne "" %then %do;
            %if %index(%lowcase(&filename),%lowcase(&iFilter)) %then %do;
              %let result = &result%str(&iDelimiter)&filename;
            %end;
          %end;
          %else %do;
            %let result = &result%str(&iDelimiter)&filename;
          %end;
        %end;
      %end;
      %else %do;
        %put ERROR: (CMN_MAC.FILE_LIST) FILE CANNOT BE READ.;
        %put %sysfunc(sysmsg());
      %end;
    %end;

  %end;
  %else %do;
    %put ERROR: (CMN_MAC.FILE_LIST) PATH DOES NOT EXIST OR CANNOT BE OPENED.;
    %put %sysfunc(sysmsg());
  %end;

  /*
  ** RETURN THE RESULT.  TRIM THE LEADING DELIMITER OFF THE FRONT OF THE RESULTS.
  */
  %if "&result" ne "" %then %do;
    %substr(&result,2)
  %end;

%mend; 



**
** EXAMPLES - HAVENT TESTED THE LAST TWO YET BUT THEY SHOULD WORK IF SYNTAX IS CORRECT
*;

%put %file_list(iPath=c:\temp);

%put %file_list(iPath=c:\xxdffsds);

%put %file_list(iPath=c:\rob\SASDev\, iFilter=a);

%put %file_list(iPath=c:\rob\SASDev\,iFiles_only=1);

%put %file_list(iPath=/tmp/unix_sasdir,iFiles_only=1);

data x;
  file_list = "%file_list(iPath=c:\temp)";
run;

proc sql noprint;
  insert into my_table values ("%file_list(iPath=c:\temp,iDelimiter=%str(","))");
quit;