How can I assign a heredoc to a variable in a way that's portable across Unix and Mac?

5 votes

3 answers

1138 views

shell-script macos here-document portability

This code works fine on Linux but not Mac OS:

#!/usr/bin/env bash
foo=$(cat <


It fails on Mac with
./test.sh: line 6: unexpected EOF while looking for matching `"'
./test.sh: line 7: syntax error: unexpected end of file
If I do cat < instead of foo=$(cat <, it works fine.  Is there a portable way to get heredocs (or multiline strings) into variables without using a file as an intermediate?

**Edit**: I want to use a heredoc becuase I have a multiline string with " and '.  My actual example looks like:
EXPECTED_ERROR=$(cat <



                  
                  
                    
                      
                        
                        Asked by Jason Gross
                        (173 rep)
                      
                    
                    
                      
                        
                        Sep 17, 2024, 02:55 AM
                        
                          
Last activity: Oct 9, 2024, 05:41 PM



            
            
              
              
    
      Sidebar Ad - 300x250
    
  

              
              
                
                  Related Questions
                
                
                  
                    
                      Browse more questions from Unix & Linux Stack Exchange
                    
                  
                  
                    
                      
                        More questions tagged "shell-script"
                      
                    
                  
                    
                      
                        More questions tagged "macos"
                      
                    
                  
                    
                      
                        More questions tagged "here-document"