Identify the files opened a particular process on linux

I need a script to identify the files opened a particular process开发者_StackOverflow on linux

To identify fd :

>cd /proc/<PID>/fd; ls |wc –l  

I expect to see a list of numbers which is the list of files descriptors' number using in the process. Please show me how to see all the files using in that process. Thanks.

The command you probably want to use is lsof. This is a better idea than digging in /proc, since the command is a more clear and a more stable way to get system information.

lsof -p pid

However, if you're interested in /proc stuff, you may notice that files /proc/<pid>/fd/x is a symlink to the file it's associated with. You can read the symlink value with readlink command. For example, this shows the terminal stdin is bound to:

$ readlink /proc/self/fd/0
/dev/pts/43

or, to get all files for some process,

ls /proc/<pid>/fd/* | xargs -L 1 readlink

While lsof is nice you can just do:

ls -l /proc/pidoftheproces/fd

lsof -p <pid number here> | wc -l

if you don't have lsof, you can do roughly the same using just /proc

eg

$ pid=1825
$ ls -1 /proc/$pid/fd/*
$ awk '!/\[/&&$6{_[$6]++}END{for(i in _)print i}' /proc/$pid/maps

You need lsof. To get the PID of the application which opened foo.txt:

lsof | grep foo.txt | awk -F\  '{print $2}'

or what Macmede said to do the opposite (list files opened by a process).

lsof | grep processName