fuser command
fuser shows processes using files or sockets
Typical usage: diagnosing network issues, disk operations, information gathering, troubleshootingIntroduction into fuser
The fuser command is a tool for Linux systems to quickly identify which processes have a file or socket opened. This can be useful during unmounting a file system or finding our what processes have a connection active.
Installation
When fuser is not installed by default, it can be added to the system using the relevant software package.
Package information for fuser
| Operating system | Package name | Installation |
|---|---|---|
| AlmaLinux | psmisc | |
| Arch Linux | psmisc | |
| Debian | psmisc | |
| Fedora | psmisc | |
| Red Hat Enterprise Linux | psmisc | |
| Rocky Linux | psmisc | |
| openSUSE | psmisc | |
| Ubuntu | psmisc | |
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Usage
Available options
| Long option | Short option | Description |
|---|---|---|
| --interactive | -i | Before killing a process (see --kill), ask confirmation |
| --kill | -k | Kill the process(es) that have the file or socket open |
| --mount MOUNTPOINT | -m MOUNTPOINT | Show processes that have file open at specified mount point |
| --ipv4 | -4 | Only search for IPv4 sockets |
| --ipv6 | -6 | Only search for IPv6 sockets |
| --verbose | -v | Verbose output to show more details |
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Examples using fuser
Show which processes have TCP port 22 socket open including details
fuser --verbose --ipv4 22/tcpSelect namespace 'tcp' and select port 22 to see which processes have the socket open with verbose for details
fuser --verbose --namespace tcp 22Show all processes that have a file open at the specified mount point
fuser --verbose --mount /mnt/mydataFrequently Asked Questions
What is the fuser command and its purpose?
The fuser command is a command-line tool to show which processes have a file or socket opened
Which package provides the fuser command?
The command fuser is provided by the psmisc package.
Related and similar commands
Linux has a lot of tools and commands available and sometimes you just need that little other tool. Here is a list of commands that are similar or related to fuser:
| Command | Category | Summary |
|---|---|---|
| basename | files | Strips directory and file name suffix from a given path |
| lsfd | files | Shows open file descriptors for processes |
| lsof | files | Shows open files and sockets |
| watch | processes | Monitors changes in output of specified command |