轉載 自https://unix.stackexchange.com/questions/333186/how-to-list-the-open-file-descriptors-and-the-files-they-refer-to-in-my-curren

Yes, this will list all open file descriptors:

$ ls -la /proc/$$/fd
total 0
dr-x------ 2 sorontar sorontar  0 Dec 28 00:56 .
dr-xr-xr-x 9 sorontar sorontar  0 Dec 28 00:56 ..
lrwx------ 1 sorontar sorontar 64 Dec 28 00:56 0 -> /dev/pts/6
lrwx------ 1 sorontar sorontar 64 Dec 28 00:56 1 -> /dev/pts/6
lrwx------ 1 sorontar sorontar 64 Dec 28 00:56 2 -> /dev/pts/6
lrwx------ 1 sorontar sorontar 64 Dec 28 00:56 255 -> /dev/pts/6
l-wx------ 1 sorontar sorontar 64 Dec 28 00:56 4 -> /home/sorontar/testfile.txt
 

Of course, as usual: 0 is stdin, 1 is stdout and 2 is stderr.
The 4th is an open file (to write) in this case.