check service status

[vitorgatti]

how can I check a service status, returning this as a boolean or number value?

I am trying to do this with grep, but it is not working well:
example: to check samba's status

	if [ `ps aux |grep -c smb` -gt 0 ]
	then
		echo "active"
	else
		echo "not active"
	fi

BECAUSE, sometimes I get this value:
2841 ? Ss 0:00 /usr/sbin/smbd -D
2870 ? S 0:00 /usr/sbin/smbd -D
24815 pts/0 R+ 0:00 grep smb

AND sometimes this:
2841 ? Ss 0:00 /usr/sbin/smbd -D
2870 ? S 0:00 /usr/sbin/smbd -D

where is the last line?
and, because of that, sometimes this script works, and sometimes not.
well, if there is another way to get that...

I am using a Debian-based distro

thanks :)

[i92guboj]

how can I check a service status, returning this as a boolean or number value?

I am trying to do this with grep, but it is not working well:
example: to check samba's status

	if [ `ps aux |grep -c smb` -gt 0 ]
	then
		echo "active"
	else
		echo "not active"
	fi

BECAUSE, sometimes I get this value:
2841 ? Ss 0:00 /usr/sbin/smbd -D
2870 ? S 0:00 /usr/sbin/smbd -D
24815 pts/0 R+ 0:00 grep smb

AND sometimes this:
2841 ? Ss 0:00 /usr/sbin/smbd -D
2870 ? S 0:00 /usr/sbin/smbd -D

where is the last line?
and, because of that, sometimes this script works, and sometimes not.
well, if there is another way to get that...

I am using a Debian-based distro

thanks

There must be a more debianish way to do that. But your script is not working because you are misunderstanding one thing:

In `ps aux |grep -c smb`, the returned state would be this of grep. Grep does not automatically return the number of lines it finds (that seems to be what you thought). Instead, grep returns 0 on success, and any other number on error (just like 99% of the linux programs). So, you need to check for -eq 0 (or == 0), like this:

if [ `ps aux | grep -c smb` -eq 0 ]

Alternatively, if you really want to know the number of lines it finds, you can use something like:

if [ `ps aux | grep -c smb | wc -l` -gt 0 ]

I didn't test any of these, but they should work.

EDIT: Sorry, I overlooked your -c in the grep command. I will leave the above as a refference, but that seems not to be your problem. Anyway, what do you want the number of lines for?

Indeed, you should be looking for this instead:

if [ `ps aux | grep smb | grep -c -v grep` -gt 0 ]

So, the grep process, will not count itself.

[vitorgatti]

whoa, this "-v" worked perfectly!

I am counting line numbers so I can guess if the process exists or not (so it is active), but that "grep" appearing sometimes and sometimes not was making everything more difficult

thanks a lot :D