How does `fopen` before `rename` still reads the old content using PHP
The code below opens a file descriptor ($fp) to a specific file, then I overwrite that file (using rename) and then later I read the content of that file using fread. What amazes me is that when reading the file using fread it still points to the content of the original file (before being overwritten)! How does this happen? I think this could only be possible if fopen made an entire copy of the file so it can be read later, but I cant believe fopen makes and entire copy of the file because this would be very inneficient.
How does `fopen` before `rename` still reads the old content using PHP
The code below opens a file descriptor ($fp) to a specific file, then I overwrite that file (using rename) and then later I read the content of that file using fread. What amazes me is that when reading the file using fread it still points to the content of the original file (before being overwritten)! How does this happen? I think this could only be possible if fopen made an entire copy of the file so it can be read later, but I cant believe fopen makes and entire copy of the file because this would be very inneficient.