Is there any reasons to not use "mmap" to read files?

[Ali Çehreli]

On 2/12/22 05:17, rempas wrote:

 > a system call every single time

I have a related experience: I realized that very many ftell() calls 
that I were making were very costly. I saved a lot of time after 
realizing that I did not need to make the calls because I could maintain 
a 'long' variable to keep track of where I was in the file.

I assumed ftell() would do the same but apparently not.

Ali