execute a command

Question

I have script file where a command is stored in a variable

First i got the command (assume "ls -l " command)

cmd=`cat /proc/2345/cmdline`

now doing

echo $cmd

outputs

ls -l

Now how to use $cmd to actually execute that command. which is ls -l

Answer 1

BASH FAQ entry #50.

Answer 2

The simple answer is:

$cmd

Answer 3

if you have no business to store it in a variable, then don't. Just run it as usual.

cat /proc/2345/cmdline

Answer 4

eval $cmd

Just $cmd will work in many cases, but not always. See the article "Bash: Why use eval with variable expansion?" for further details.