procfs (or the proc filesystem) is a special filesystem in UNIX-like operating systems that presents information about processes and other system information in a hierarchical file-like structure

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Why doesn't INotify work with `/etc/mtab` or `/proc/mounts`? [duplicate]

When I used INotify with /etc/mtab or /proc/mounts, it doesn't detect changes when things mount or unmount, even though /etc/mtab and /proc/mounts both have changed when I check manually. Why is this, ...
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Encoding of /proc/<pid>/cmdline files

I am thinking about working with the /proc/<pid>/cmdline files, but I couldn't find any documentation about the file encoding. The only piece of information I could find is located in the man ...
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197 views

Memory usage of a given process (using Linux proc filesystem)

I want to know which files from /proc directory and which fields of these files I need to calculate the memory usage of a given pid. I've been using the "stat" file and the "vsize" parameter that is ...
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Directory in /proc that isn't process dir but start with number?

Quick question. Is it possible to create directory in /proc that starts with number but isn't process directory (where name is PID)? I write software that searches for process directories and I wonder ...
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List running processes without procfs

I'd like to list running process (like using ps or top), but there is no procfs mounted. The procfs not being mounted is intentional, and is made to prevent malicious user to access systems ...
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With “find /”, skip directories like “/proc”, “/sys” and similar [duplicate]

There are some directories that can cause problem with find, and especially find /. These are directories in which the OS creates files which are not really files. Among these directories are /proc ...
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Looking for /procfs documentation, describing values and units of measurement

Surprisingly, comprehensive documentation for /procfs is hard to find. For my specific question, I am looking at: cat /proc/1/statm (let's use pid=1 because it seems to be always there). I just ran ...
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Get the process start time irrespective of NTP updates

I'm trying to record the start time of a process kicked off by an @reboot cronjob. I'm using ps -p $$ -o ltime= presently, but I've run into a catch. My machine (a Raspberry Pi) connects to the ...
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What is /proc/dma? Is it just for legacy support?

I reading a Linux book that told me I can check the dma channels by reading /proc/dma. This is what I see when I run cat /proc/dma: 2: floppy 4: cascade I'm confused because that looks like old ...
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262 views

How to get UID and PID

So here's what I want to do: User inputs a USERNAME. Based on this username, I need to get the list of processes started by this user. I am planning to do this by getting the UID of this user and ...
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Modify 'Soft Limit' of 'Max processes'

I tried ulimit -u 2000 and ulimit -Su 2000 to modify the 'Max processes', and started up my program, but failed. I found file '/proc/pid/limit' is still: Max processes 1024 ...
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Ubuntu: /proc/pid/comm file missing

On my development box, under /proc/[pid]/ there is a file called comm containing the name of the executable for that process. I use this to validate the process to which I am sending a signal. On our ...
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How to clone a read-only portion of /proc file system

The problem with reading /proc file system is that it is not atomic. I tried using a library (procfs in Python) that wishes to read it, but it has glitches about 5% of the time because the process ...
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716 views

vmstat on virtual machine and large values

Hi I'm using vmstat to track machine performance during some tests (jmeter). This is virtual machine running on a big machine where lots of other virtual machines are installed (about 20 virtual ...
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Duration of /proc/pid/stat

I have a process that starts a child process and when the child exits, scans /proc/<pid>/stat to gather some information about the CPU and memory the child used. However I am worried that I am ...
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154 views

Unable to read /proc/pid/stack file even with proper permissions

As far as i know, i should be able to read a regular file contents if i have the permissions to do so. Following is the output of ls -l stack for the stack file (/proc/pid/stack) for one of the ...
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169 views

Is there any way to read files from the virtual /proc directory using smbclient?

Is there any way to read files from the virtual /proc directory using smbclient? No root access. Both server and client are Debian Linux machines. Server is running Samba 3. Smbclient version is ...
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processor(s) statistics that is one day old

I already know how to use grep -w cpu /proc/stat in order to get the cpu stats and identify the user mode. Percentage wise, I just divide it my the total time from the /proc/uptime. However, how can ...
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524 views

Do kernel counters for jiffies in state exist in Linux?

I am looking to get time/jiffie stats on the state of a daemon process. The states I'm referring to are mentioned in the Linux Kernel Proc Filesystem document. Running, Sleeping, uninterruptible ...
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457 views

About sector and blocks, and a little confusion in /proc/diskstats

I've been studying about diskstats lately, and I get that the amount of hdd read comes in sectors. But in most places I've noticed that there exists a slight misunderstanding about sectors and blocks. ...
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Connecting various process attributes reported by top, ps, /proc/pid/statm, /proc/pid/status, /proc/pid/smaps [closed]

Here are some of the common attributes I figured out: top(VIRT) , smem(VSS), /proc/pid/statm (1st entry in pages), /proc/pid/status (VmSize), ps(VSZ) top(RES) , smem(RSS), /proc/pid/statm (2nd entry ...
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Get Linux architecture from /proc filesystem

I'm writing a program in Java and I need to determine the architecture for which Linux was compiled. I need something like uname -m, but without running any program, but instead from the /proc ...
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Recover from faking /proc/meminfo

So, without really thinking too much, I ran this script: #!/bin/bash SWAP="${1:-512}" NEW="$[SWAP*1024]"; TEMP="${NEW//?/ }"; OLD="${TEMP:1}0" sed "/^Swap\(Total\|Free\):/s,$OLD,$NEW," /proc/meminfo ...
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cannot read key “net.ipv6.conf.all.stable_secret” in sysctl?

I am running kernel version as followings on an Arch Linux computer: [root@router ~ ]$ uname -a Linux router 4.2.5-1-ARCH #1 SMP PREEMPT Tue Oct 27 08:13:28 CET 2015 and I noticed that every time ...
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What is the BOOT_IMAGE parameter in /proc/cmdline

I'm currently reading the book How Linux Works and in chapter 5 it talks about Linux parameters. Curious I started to see what were the parameters passed to my installed kernel when it boots up and ...
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Why is the size of “/proc/kcore” file so bigger than the physical memory size?

From proc manual: /proc/kcore This file represents the physical memory of the system and is stored in the ELF core file format. With this pseudo-file, and an unstripped kernel ...
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There is no /proc/bus/usb directory

I'm running a centos VM on ESXi. Does the /proc/bus/usb directory not show up until a USB device is connected? I just added a USB controller to the VM (it previously had non) and ran lsusb: $ ...
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proc system interrupts information

There are many info under /proc For examples, for each process : raw format : cat /proc/< pid >/stat human readable : cat /proc/< pid >/status My goal is to read the info ...
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code generating /proc file system

In my assignment, I have added "casper" flag to task descriptor and it takes only 0, 1, 2 and 3 (default 0). I asked to "modify the code that generates the /proc filesystem so that its behavior is ...
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48 views

What does the “ss -s” result “Total:” value represent? How to get details on each of them?

I am trying to understand what the ss -s result line Total: value represents, along with how this number is related to the other numbers. Note, the following values are equivalent: ss -s Total: == ...
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Inconsistent output on /proc. Can some processes be hidden? [duplicate]

When I list /proc/<PID>, works as expected. But when I use ps or ls /proc | grep <PID>, the process is hidden. How & Why is this possible? [user@host ~]$ ls /proc/12263 attr ...
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What is kswapd_low_wmark_hit_quickly from /proc/vmstat

What does this parameter mean? # cat /proc/vmstat | grep low kswapd_low_wmark_hit_quickly 2
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How to know file name of sockets or pipes in /proc/[pid]/fd

In Android, #ls -l 15843/fd gives following output, lrwx------ u0_a179 u0_a179 2015-05-28 11:58 90 -> socket:[193728] lrwx------ u0_a179 u0_a179 2015-05-28 11:58 91 -> ...
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What are possible reasons why iwconfig is not updating connection stats?

I use iwconfig to show me some information about my current internet connection like this $ iwconfig wlp2s0 IEEE 802.11abg ESSID:"eduroam" Mode:Managed Frequency:2.462 GHz Access ...
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How can I get read/write instant speed of a Hard Drive using /proc/diskstats data?

I know that the proc/diskstats file presents these data columns: 1 - major number 2 - minor mumber 3 - device name 4 - reads completed successfully 5 - reads merged 6 - sectors read 7 - time spent ...
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Constant 60KB Shared library memory on /proc/<pid>/maps [duplicate]

In a quest for understanding RAM requirements of system processes, I arrived to analysis of /proc/pid/maps. I have noticed a pattern: many shared libraries have exactly 60KB space allocated in their ...
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116 views

How to see kernel time variables without using adjtimex?

The man page for adjtimex says Anyone may print out the time variables, but only the superuser may change them. How do I see the value shown by adjtimex -p as the tick variable without using ...
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/proc/stat - is guest counted into user time?

I have a quick question. In man page for /proc/stat this is not clear to me: Is guest and guest_nice time included in user time in /proc/stat? http://man7.org/linux/man-pages/man5/proc.5.html in ...
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323 views

How is /proc/net files getting populated in Linux/Unix?

I'm working on a network monitor for Linux, without packet sniffing. I'm planning to read the network statistics and related data from /proc/net files. I know that /proc is the mount point of process ...
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550 views

Permission denied on aio-max-nr file

I would like to edit the file aio-max-nr: root@node:~# echo 65536 > /proc/sys/fs/aio-max-nr -su: /proc/sys/fs/aio-max-nr: Permission denied Knowing that : root@node:~# ls -lrth ...
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How does /proc/$PID/fd actually work? [duplicate]

According to the terse documentation I managed to find, each file in /proc/$PID/fd is supposed to be a symlink to the actual file associated with that file descriptor. However, that doesn't appear to ...
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236 views

Value of /proc/sys/kernel/hostname

I've set computer hostname in /etc/hostname a while ago (also there are record in /etc/hosts). Everything worked fine, but recently I've noticed that value of hostname (and /proc/sys/kernel/hostname) ...
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152 views

Viewing shared segments created by shmget

I'm trying to "visualize" shared memory between two processes. I've created a little server-client example where the client writes some data to a shared memory location and the server reads from it. ...
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Determine how much a process is using each disk?

How do I tell how much load a particular process is contributing to each of several available volumes/mounts? It seems that dstat only shows aggregate stats across all processes per disk, and iotop ...
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how long use of linux? [duplicate]

/proc/uptime shows how long the system has been running since the last time I turned it on. Is there a way to determine the total amount of time the system has ever been on since I first installed it? ...
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Process VSS and Size: entry in /proc/pid/smaps

I was wondering why the sum of all 'Size:' entries in /proc/pid/smaps does not equal the process VSS as reported by top, ps, /proc/pid/status VmSize, /proc/pid/statm 1st entry? Any clues?
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Rogue Java process brings my computer to a halt

In reference to my earlier post: Is there a log of past threads that are now closed? I gave the process a kill -STOP signal and started examining the details. I can't seem to figure out why it is ...
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Why would the size of /proc/stat show as zero? [duplicate]

ls -rlth /proc/stat -r--r--r-- 1 root root 0 Feb 21 04:25 /proc/stat Although if we cat it, its got enough contents. Any help regarding this virtual FS will be helpful.
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Awk run time error: not enough arguments passed

Here is the script: TYPE="${BLOCK_INSTANCE:-mem}" awk -v type=$TYPE ' /^MemTotal:/ { mem_total=$2 } /^MemFree:/ { mem_free=$2 } /^Buffers:/ { mem_free+=$2 } /^Cached:/ { mem_free+=$2 ...
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How to get total disk read/write in bytes per hdd device from /proc

How to get total disk read/write in bytes per hdd device? for example if i have sda, sdb, and sdc, is there any file on /proc that i could use similar to /proc/net/dev for networking?