What's the fastest way using lsof to find a single open file?

Posted by jjclarkson on Stack Overflow See other posts from Stack Overflow or by jjclarkson
Published on 2010-03-26T21:56:42Z Indexed on 2010/03/26 22:03 UTC
Read the original article Hit count: 369

Filed under:

linux

|

lsof

|

files

|

php

I'm trying to test a single file if it is open using lsof. Is there a faster way than this?

$result = exec('lsof | grep filename | wc -l');

if($result > 0) {
    //file is open
}

I'm thinking their must be a way to just test for one file if you know the filename. All I really need is a true or false.

© Stack Overflow or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about lsof

lsof not showing what port a proc is listening on

as seen on Server Fault - Search for 'Server Fault'
I have many processes on a box listening on several ports. I am trying to map ports to pids. The problem is that lsof is not telling me what ports belong to which process. Given an apache listening on port 80, I can see it listening via netstat: user@host% netstat -an|grep LISTEN|grep 80 *.80 … >>> More
txt file descriptor in lsof

as seen on Server Fault - Search for 'Server Fault'
In my experience, files that have the file descriptor of txt in lsof output are the executable file itself and shared objects. The lsof man page says that it means "program text (code and data)". While debugging a problem, I found a large number of data files (specifically, ElasticSearch database… >>> More
Why doesn't lsof show localhost TCP connections in 14.04?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I have two servers running 12.04.4 and 14.04.1 respectively. Both have nginx (port 80) and a Java process (port 8080). As expected, the lsof output for the Java process on the 12.04 machine shows a couple of established connections for port 8080 (e.g. TCP 127.0.0.1:8080->127.0.0.1:58067 (ESTABLISHED)) The… >>> More
How can I unbind a UDP port that has no entry in lsof?

as seen on Super User - Search for 'Super User'
On my Mac, I have a UDP port that is "already in use", but doesn't have an associated process: sudo netstat -na | grep "udp.*\.500\>" shows udp4 0 0 192.168.50.181.500 *.* udp4 0 0 192.168.29.166.500 *.* … >>> More
What's the fastest way using lsof to find a single open file?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm trying to test a single file if it is open using lsof. Is there a faster way than this? $result = exec('lsof | grep filename | wc -l'); if($result > 0) { //file is open } I'm thinking their must be a way to just test for one file if you know the filename. All I really need is a true… >>> More