How to select columns only containing the certain string in SAS [duplicate]

There's several variations on how to filter out names.

For prefixes or lists of variables it's pretty easy. For suffixes or more complex patterns it keeps more complicated. In general you can short cut lists as follows:

_numeric_ : all numeric variables
_character_ : all character variables
_all_  : all variables
prefix1 - prefix# : all variables with the same prefix assuming they're numbered
prefix:  : all variables that start with prefix
firstVar -- lastVar : variables based on location between first and last variable, including the first and last. 
first-numeric-lastVar : variables that are numeric based on location between first and last variable

Anything more complex requires that you filter it via the metadata list. SAS basically keeps some metadata about each data set so you can query that information to build your lists. Data about columns and types are in the sashelp.vcolumn or dictionary.column data set.

To filter all columns that have the word mpg for example:

*generate variable list;
proc sql noprint;
select name into :var_list separated by " "
from sashelp.vcolumn

where libname = 'SASHELP' and memname = 'CARS' 
and lowcase(name) like '%mpg%';
quit;

*check log for results;
%put &var_list;

*verification from original table;
proc contents data=sashelp.cars;
run;

*example of usage;
data want;
set sashelp.cars;
keep &var_list;
run;

Some more details are available in this blog post and here (documentation).

If you want do keep only variables that start with an s, then use name prefix list operator :.

data want;
   set have(keep=s:);
run;

It's possible. In the code below I created a macro variable that has the name of columns that have in a table. After run the code you will have the name of columns you want.

PROC SQL;
   SELECT 
    NAME
INTO:
    NMVAR /*    SAVE IN MACRO VARIABLE  */
FROM SASHELP.VCOLUMN
WHERE 
    LIBNAME EQ "YOUR LIBNAME" AND /* THE NAME OF LIB MUST BE WRITTEN IN UPPERCASE */
    MEMNAME EQ "YOUR TABLE" AND /* THE NAME OF 'TABLE/DATA SET' MUST BE WRITTEN IN UPPERCASE */
    SUBSTR(NAME,1,1) EQ "S";

RUN;