Every day a Linux command (--lsof) FD file descriptor

The general lsof will output the following information:

COMMAND: Name of the process

PID: Process Identifier

PPID: Parent Process Identifier (the-R parameter needs to be specified)

USER: Process Owner

Pgid: The group to which the process belongs

FD: File descriptor in which the application recognizes the file through a file descriptor.

Type: File type. such as DIR, Reg, etc.

DEVICE: Specifies the name of the disk

Size: Sizes of files

Node: Index node (the identity of the file on disk)

Name: Open the exact name of the file

　　　　

This focus is on the FD file descriptor, because in lsof this content occupies a large space, I have always been advocating simplification, so I took it out of the study alone.

Fd:

(1) CWD: Represents the current working dirctory, which is the directory in which the application starts, unless it makes changes to the directory itself

(2) TXT: This type of file is a program code, such as the application binary file itself or a shared library, as shown in the list above/sbin/init program

(3) Lnn:library references (AIX)

(4) ER:FD information error (see NAME column)

(5) Jld:jail directory (FreeBSD)

(6) Ltx:shared Library text (code and data)

(7) Mxx:hex memory-mapped type number XX.

(8) M86:dos Merge mapped file

(9) mem:memory-mapped file

(Ten) mmap:memory-mapped device

(one) Pd:parent directory

(Rtd:root directory)

(Tr:kernel) trace file (OpenBSD)

(+) v86 Vp/ix mapped file

(15) 0: Indicates standard output

(16) 1: Indicates standard input

(17) 2: standard error indication

Generally after standard output, standard error, standard input followed by file state mode: R w u, etc.

(1) U: Indicates that the file is open and in read/write mode

(2) R: Indicates that the file is open and is in read-only mode

(3) W: Indicates that the file is open and in write-only mode

(4) Space: Indicates that the file's status mode is unknown and is not locked

(5)-: Indicates that the file's state mode is unknown and is locked

At the same time, after the file state mode, followed by the relevant lock

(1) n:for a Solaris NFS lock of unknown type

(2) R:for A read lock on part of the file

(3) R:for A read lock on the entire file

(4) W:for a write lock on part of the file (partial write lock of files)

(5) W:for A write lock on the entire file (the write lock for the entire document)

(6) U:for a read and write lock of any length

(7) U:for a lock of unknown type

(8) x:for an SCO openserver Xenix lock in part of the file

(9) x:for an SCO opentserver Xenix lock on the entire file

(Space:if there) is no lock

Every day a Linux command (--lsof) FD file descriptor