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Hello all,
I have these errors when I try to implement the script on my server: Ubuntu 18 and Nagios 4.4.6

Website:
(No output on stdout) stderr: /usr/local/nagios/libexec/check_mem01.sh: 23: /usr/local/nagios/libexec/check_mem01.sh: [[: not found


Localhost -> Service
define service {
use local-service
host_name localhost
service_description Memory Usage
check_command check_memory!95%!97%
}
"If I change the last line by check_memory -w 10 -c 5 the system shows me:
'check_memory -w 10 -c 5' specified in service 'Memory Usage' for host 'localhost' not defined anywhere!


commands.cfg:
define command {
command_name check_memory
command_line $USER1$/check_mem01.sh -w -c
}

Thanks in advance!