BASH: Execute commands stored in array-CodePudding

I am trying to execute a shell script like below

cmds=('uptime' 'free -m' 'nproc')
for cmd in ${cmds[@]};
do
echo $($cmd)
done

Execution is breaking when it comes to free -m execution because of space.

vagrant@vagrant-ubuntu-trusty-64:~$ bash for_my_script.sh
 03:42:50 up 56 min,  1 user,  load average: 0.00, 0.00, 0.00
              total        used        free      shared  buff/cache   available
Mem:         499928      108516       43204        1844      348208      366140
Swap:             0           0           0
for_my_script.sh: line 5: -m: command not found

1
vagrant@vagrant-ubuntu-trusty-64:~$

I tried iterating with for by storing commands in variable

vagrant@vagrant-ubuntu-trusty-64:~$ cmds="uptime,free -m"
vagrant@vagrant-ubuntu-trusty-64:~$ for cmd in "${cmds//,/ }"; do echo "$($cmd)"; done
uptime: invalid option -- 'm'

vagrant@vagrant-ubuntu-trusty-64:~$ cmds="uptime,'free -m'"
vagrant@vagrant-ubuntu-trusty-64:~$ for cmd in "${cmds//,/ }"; do echo "$($cmd)"; done
uptime: invalid option -- 'm'

With no success.

is touching IFS is the only way for this type of problem? any inputs are much appreciated.

Thank you.

CodePudding user response：

You have to change your code from:

cmds=('uptime' 'free -m' 'nproc')
for cmd in ${cmds[@]};
do
echo $(${cmd})
done

into

cmds=('uptime' 'free -m' 'nproc')
for cmd in "${cmds[@]}";
do
echo $(${cmd})
done

You missed double quotes around ${cmds[@]}.