AIX 5L Problem Determination - IBM Redbooks

files are read-only, but some of them can also be written to and be used for
process control purposes.
The ownership of the files in the /proc file system is the same as for the
processes they represent. Therefore, regular users can only access /proc files
that belong to their own processes. For example, a process is waiting for
standard input. When you look at an active process, a lot of the information
would constantly change:
# errpt -a|more
.....
.....
# ps -ef|grep errpt
root 12586 17594 1 16:53:00 pts/3 0:00 grep errpt
root 22214 8882 0 16:49:39 pts/1 0:00 errpt -a
# ls -al /proc/22214
total 0
dr-xr-xr-x 1 root system 0 Sep 17 16:56 .
dr-xr-xr-x 1 root system 0 Sep 17 16:56 ..
-rw------- 1 root system 0 Sep 17 16:56 as
-r-------- 1 root system 128 Sep 17 16:56 cred
--w------- 1 root system 0 Sep 17 16:56 ctl
dr-xr-xr-x 1 root system 0 Sep 17 16:56 lwp
-r-------- 1 root system 0 Sep 17 16:56 map
dr-x------ 1 root system 0 Sep 17 16:56 object
-r--r--r-- 1 root system 448 Sep 17 16:56 psinfo
-r-------- 1 root system 1024 Sep 17 16:56 sigact
-r-------- 1 root system 1520 Sep 17 16:56 status
-r--r--r-- 1 root system 0 Sep 17 16:56 sysent
Table 7-2 provides the functions of the pseudo files listed in the previous output.
Table 7-2 Functions of pseudo files in /proc/ directory
Pseudo file name Function
as Read/write access to address space
cred Credentials
ctl Write access to control process, for example, stop or resume
lwp directory Kernel thread information
map Virtual address map
object directory Map file names
psinfo Information for the ps command; readable by everyone
sigact Signal status
Chapter 7. LVM, file system, and disk problem determination 163