List all Open Files with lsof Command

In the below example, it will show long listing of open files some of them are extracted for better understanding which displays the columns like Command, PID, USER, FD, TYPE etc.

Sections and it’s values are self-explanatory. However, we’ll review FD & TYPE columns more precisely.

FD – stands for File descriptor and may seen some of the values as:

1. cwd current working directory
2. rtd root directory
3. txt program text (code and data)
4. mem memory-mapped file

Also in FD column numbers like 1u is actual file descriptor and followed by u,r,w of it’s mode as:

1. r for read access.
2. w for write access.
3. u for read and write access.

TYPE – of files and it’s identification.

1. DIR – Directory
2. REG – Regular file
3. CHR – Character special file.
4. FIFO – First In First Out