/proc File System

The/proc file system is a virtual file system in which all files in this directory do not occupy disk space, which are dynamically generated and stored in memory by the Linux kernel after it is started.

[[email protected] ~]# cd /proc[[email protected] proc]# ls1      1189  1369  1402  1909  277  38    71         cmdline       interrupts  kpageflags  net            sys10    1198  1382  142   2      278  4    732         cpuinfo      iomem       loadavg      pagetypeinfo  sysrq-trigger1032  12    1384   143   20    28   40   8           crypto       ioports     locks        partitions    sysvipc1050  1218   1386  144   2075  289  41   9           devices      ipmi         mdstat      sched_debug   timer_ list11    1238  1389  15    21     29   5    964         diskstats    irq         meminfo      schedstat     timer_stats1105  13     1393  150   22    3    541  990         dma          kallsyms     misc        scsi           tty1122  1314  1394  151   23    30    561  acpi       driver        kcore       modules     self           uptime1147  1323  1395   16    24    31   6    asound      execdomains  keys         Mounts    &nbSp; slabinfo      version1156  1338  1397  17     25    32   688  buddyinfo  fb            key-users   mpt          softirqs      vmallocinfo1157   1346  1398  18    26    369  689   bus        filesystems  kmsg         mtd         stat           vmstat1186  1357  14    19     27    37   7    cgroups     fs           kpagecount  mtrr         swaps         zoneinfo[[email  protected] proc]# echo $$   //viewing the pid1402[[email protected] proc of the current shell ]# cd 1402[[email protected] 1402]# lsattr         cmdline          environ  limits      mounts      oom_score      sched       stat     wchanautogroup   comm              exe       loginuid   mountstats  oom_score_adj  schedstat   Statmauxv        coredump_filter  fd       maps        net         pagemap         sessionid  statuscgroup       cpuset           fdinfo   mem         ns           Personality    smaps      syscallclear_refs  cwd               io        mountinfo  oom_adj     root            stack      task[[email protected]  1402]#

The directory for each process in the/proc/system contains the same project.

CmdLine: The directory contains the entire command line that started the process.

CWD: The symbolic connection points to the current working directory of the process.

Environ: This file contains all the environment variables defined for this process, in the format "variable = value"

EXE: This is a symbolic link to the executable program file that the process executes.

FD: This directory contains all the descriptors opened by the process.

Maps: When the content of the file is large, you will see that part of the process's address space that is currently mapped to the file, from left to right, the address space associated with the map, the permissions associated with that map, the offset of the map starting position, the master of the mapping file device, the sequence (16 binary), the inode ordinal, The file name of the file.

Root: The symbolic connection points to the root directory used by the process.

Status: The file contains a lot of information about the process, it can execute file name, current state, PID and Ppid, actual and valid UID and GID, memory usage load state.

The/PROC also contains various hardware information on the machine.

Cat/proc/devices//View device information in the system, including character devices and block devices Cat/proc/cpuinfo//view CPU Information Cat/proc/filesystems//view system supported file Systems CAT/PROC/IOP   Orts//View the I/O port of the system cat/proc/interrupts//View interrupt information cat/proc/modules//View the list of modules loaded in the system core cat/proc/mounts//view mounted file system cat /proc/swaps//view swap partition usage Cat/proc/partitions//view system partition information Cat/proc/version//view the current kernel version

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/proc File System