[SOLVED] quote inside a variable

elocholero · 06-09-2016, 06:30 AM

Code:

[root@localhost libexec]#  sudo -u jboss ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name="Perm Gen" -A Usage -K used | cut -d = -f 2

Anyway I could declare this as a variable, or redirect the output of this command to a one? This is already containing an quote mark, and it has to. Any help will be greatly appriciated!

TenTenths · 06-09-2016, 06:39 AM

Quote:

Originally Posted by elocholero

Anyway I could declare this as a variable, or redirect the output of this command to a one?

Yes

Quote:

Originally Posted by elocholero

This is already containing an quote mark, and it has to. Any help will be greatly appriciated!

Just escape the quote marks (") as appropriate.

elocholero · 06-09-2016, 07:34 AM

For some reason, it does not behave the same, when I am using escape:

Quote:

[root@localhost libexec]# perm_check="sudo -u root ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name=\"Perm Gen\" -A Usage -K used | cut -d = -f 2"; $perm_check
JMX CRITICAL Unterminated quoted value

[root@localhost libexec]# perm_check="sudo -u root ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name=\'Perm Gen\' -A Usage -K used | cut -d = -f 2"; $perm_check
JMX CRITICAL java.lang:type=MemoryPool,name=\'Perm

[root@localhost libexec]# perm_check="sudo -u root ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name='Perm Gen' -A Usage -K used | cut -d = -f 2"; $perm_check
JMX CRITICAL java.lang:type=MemoryPool,name='Perm

As w/o:

Quote:

[root@localhost libexec]# sudo -u root ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name="Perm Gen" -A Usage -K used | cut -d = -f 2
43166280

rknichols · 06-09-2016, 07:59 AM

Quoting gets really difficult when command lines are parsed multiple times, in this case, (1) when setting the variable, (2) when invoking that variable as a command, and (3) when sudo passes the command line to a shell for actual execution.

In general, variables are the wrong place to store command lines. It's usually much easier to define a shell function instead:

Code:

function perm_check () {
sudo -u jboss ./check_jmx -U service:jmx:remoting-jmx://localhost:4447 -O java.lang:type=MemoryPool,name="Perm Gen" -A Usage -K used | cut -d = -f 2
}

perm_check

pan64 · 06-09-2016, 08:17 AM

probably | should be quoted too, that makes it really difficult (look for evaluation order)

elocholero · 06-09-2016, 10:45 AM

Thank you guys, straight to the point. What do I pay you rknichols?

rknichols · 06-09-2016, 12:20 PM

I really can't claim that idea as my own. Maybe Al Gore came up with it back when he was inventing the Internet.