retrieve headers from proc http

[evaleah]

I am making an API GET call that returns a field I need in the headers. I am able to get the headers into a file using headerout. How do I pull a specific header value into a variable? Here is what I part of the output from headerout.

Server: Microsoft-IIS/10.0
X-AspNetMvc-Version: 3.0
X-MWS-CV-Last-Updated: 2020-12-07T21:54:45
X-AspNet-Version: 4.0.30319

I need to retrieve just X-MWS-CV-Last-Updated. Is there a way to do that short of text parsing the entire thing?

[RichardDeVen · Accepted solution]

There is no built-in reader for parsing header files.  You can perform simple text processing as follows to get either name/value data set, or single row table after transposing.

Example:

filename header temp;

* simulate header returned from API GET call;
data _null_;
  file header; input; put _infile_; datalines;
Server: Microsoft-IIS/10.0
X-AspNetMvc-Version: 3.0
X-MWS-CV-Last-Updated: 2020-12-07T21:54:45
X-AspNet-Version: 4.0.30319
;

data header_items;
  length name value $200;

  infile header;
  input;

  _cpos = index(_infile_,':');

  name  = substr(_infile_,1,_cpos-1);
  value = substr(_infile_,_cpos+1);
run;

proc transpose data=header_items out=header_vars(drop=_name_);
  id name;
  var value;
run;

Name Value pairs

Header attribute name as column name (after transpose)