I am new to linux, shell scripting, and trying to learn the fundamentals. I am currently on redirection chapter, where here document is being explained. I could not really understand how below works in conjunction with cat command. If some one can please tell me?

cat << EOF line1 line2 line3 EOF 

I very well understand how << EOF works. Keyword denotes end of input. My question is; cat takes filename as input stream; so that it can print its content on output stream. How does above work internally? We are not specifying filename anywhere. Does shell create internally some temp file and give it to cat? I hope my question is clear.

I am new to Linux, shell scripting, and I'm trying to learn the fundamentals. I am currently on the redirection chapter, where here-documents are being explained. I could not really understand how the code below works in conjunction with the cat command. If some one can please tell me?

cat << EOF line1 line2 line3 EOF 

I very well understand how << EOF works. The keyword denotes the end of input. My question is; cat takes filename(s) as input stream; so that it can print its content on output stream. How does above work internally? We are not specifying filename anywhere. Does the shell create internally some temporary file and give it to cat? I hope my question is clear.

I am new to linux, shell scripting, and trying to learn the fundamentals. I am currently on redirection chapter, where here document is being explained. I could not really understand how below works in conjunction with cat command. If some one can please tell me  ?

cat << EOF line1 line2 line3 EOF

I very well understand how << EOF works. Keyword denotes end of input. My question is; cat takes filename as input stream; so that it can print its content on output stream. How does above work internally  ? We are not specifying filename anywhere. Does shell create internally some temp file and give it to cat ? I hope my question is clear.

I am new to linux, shell scripting, and trying to learn the fundamentals. I am currently on redirection chapter, where here document is being explained. I could not really understand how below works in conjunction with cat command. If some one can please tell me?

cat << EOF line1 line2 line3 EOF 

I very well understand how << EOF works. Keyword denotes end of input. My question is; cat takes filename as input stream; so that it can print its content on output stream. How does above work internally? We are not specifying filename anywhere. Does shell create internally some temp file and give it to cat? I hope my question is clear.