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／proc directory

Created on · Last Modified on

https://www.linux.com/news/discover-possibilities-proc-directory/

The /proc directory is a strange beast. It doesn’t really exist, yet you can explore it. Its zero-length files are neither binary nor text, yet you can examine and display them. This special directory holds all the details about your Linux system, including its kernel, processes, and configuration parameters.

Under Linux, everything is managed as a file; even devices are accessed as files (in the /dev directory). Although you might think that “normal” files are either text or binary (or possibly device or pipe files), the /proc directory contains a stranger type: virtual files. These files are listed, but don’t actually exist on disk; the operating system creates them on the fly if you try to read them.

Most virtual files always have a current timestamp, which indicates that they are constantly being kept up to date. The /proc directory itself is created every time you boot your box. You need to work as root to be able to examine the whole directory; some of the files (such as the process-related ones) are owned by the user who launched it. Although almost all the files are read-only, a few writable ones (notably in /proc/sys) allow you to change kernel parameters.

directory

description

/proc/1
  • a directory with information about process number 1
  • Each process has a directory below /proc with the name being its process identification number

/proc/cpuinfo
  • Information about the processor, such as its type, make, model, and performance

/proc/devices
  • List of device drivers configured into the currently running kernel

/proc/dma
  • Shows which DMA channels are being used at the moment

/proc/filesystems
  • Filesystems configured into the kernel

/proc/interrupts
  • Shows which interrupts are in use, and how many of each there have been

/proc/imports
  • which I/O ports are in use at the moment

/proc/kcore
  • an image of the physical memory of the system
  • this is exactly the same size as your physical memory, but does not really take up that much memory; it is generated on the fly as programs access it
  • remember: unless you copy it elsewhere, nothing under /proc takes up any disspace at all

/proc/kmsg
  • Messages output by the kernel. These are also routed to syslog

/proc/ksyms
  • symbol table for the kernel

/proc/loadavg
  • The `load average’ of the system; three meaningless indicators of how much work the system has to do at the moment

/proc/meminfo
  • information about memory usage, both physical and swap

/proc/modules
  • which kernel modules are loaded at the moment

/proc/net
  • status information about network protocols

/proc/self
  • a symbolic link to the process directory of the program that is looking at .rpco
  • when two process look at /proc, they get different links. this is mainly a convenience to make it easier for programs to get at their process directory

/proc/stat
  • various statistics about the system, such as the number of page faults since the system was booted

/proc/uptime
  • the time the system has been up

/proc/version
  • the kernel version