Interested to Buy Any Domain ? << Click Here >> for more details...
What does the following command line produce? Explain each
aspect of this line.
$ (date ; ps -ef | awk {print $1}' | sort | uniq | wc -l )
>> Activity.log
- 4 Answers
- 10575 Views
- Cisco, I also Faced
- E-Mail Answers
Answer Posted / alf55
There is one thing different between who and this command in
that there are processes on the system that are run as
daemons and they will end up in the count (so nicely
described in answer #3). But as pointed out in answer #2,
it does include the header line entry in its count. To fix
that problem, (date ; ps -ef | sed '1 d' | cut -d\ -f1 |
sort -u | wc -l) >> Activity.log
could be used.
The "sed '1 d' " will delete the first line (removing the
header line
the "cut -d\ -f1" (Note there a space after the "\" and
then another space for the field separator.) which is the
same as "awk '{print $1}'".
the "sort -u" does the same work as "sort | uniq".
The ">> Activity.log" is a redirection that appends so date
and the count is append to the current data in the file
"Activity.log". Note: is will not show the ">>" as shown in
answer #3.
Examples of users that will show up in this script that will
not show up using "who | cut -d\ -f1 | sort -u | wc -l":
apache
messagebus
haldaemon
dhcp
lighttp
postmaster
ldap
mysql
postgres
memcached
openvpn
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
Which command is used to find what is in your home directory?
What is cat command in linux?
tell me something about linux commands.
Why is linux cpu usage so high?
How to know linux os is 32 bit or 64 bit?
What is phony in makefile?
What is type command in linux?
What is bc command in unix?
How do I check memory usage on linux?
What does history command do in linux?
How do I check cpu usage?
What the command used for list the contents of your home directory, current directory and all subdirectories?
What are the ms dos commands?
How do I run a .sh file in linux?
What is the syntax of mkdir?
