title: Help with File descriptors in Unix
body: <p>Every process has a file descriptor table (FDT) and each file has a file descriptor. The file descriptors for stdin, stdout and stderr are 0,1, and 2. These values are same for all processes. The FDT I believe contains references to the INODE entries of those file. The file descriptors are reused across processes i.e. they are not globally unique. Is there a global FDT maintained by kernel to which each process' FDT references? What do FDT for stdin, stdout and stderr correspond to? Are these special files linked to the keyboard, display etc. 
  Please provide links to articles, books etc.</p>