how to evaluate variable values, details inside

gglq000 · 06-09-2016, 08:45 PM

I needed to create array of commands and execute it. However due to some of the commands having space, I had to enclose in single quotes. The only issue is within each commands there are variable that should be evaluated to its values during execution which apparently not happening because I enclosed in single-quotes. Any way to evaluate those during loop?

TOOL_COMMANDS=(\
'cd $LINPACK_LOC' \
'nohup tar -xvf $LINPACK_LOC/$LINPACK_NAME' \
'mv $LINPACK_LOC/$LINPACK_INSTALL_DIR_NAME $LINPACK_LOC/linpack' \

for i in "${TOOL_COMMANDS[@]}"
do
echo command: $i
# $i
done

output:
executing commands needed to setup tools:
command: cd $LINPACK_LOC
command: nohup tar -xvf $LINPACK_LOC/$LINPACK_NAME
command: mv $LINPACK_LOC/$LINPACK_INSTALL_DIR_NAME $LINPACK_LOC/linpack
command: cd $PMEMTEST_LOC
command: nohup tar -xvf /$PMEMTEST_LOC/$SYSDIAG_NAME

lazardo · 06-10-2016, 12:41 AM

[ ? Single quotes prevent variable substitution ]
[ ? Missing closing ')' ]
[ ? CODE tags around code when posting ]

[ bash 4.3 ]

Code:

$ subme=123
$ test=(
   "its a test"
   for
   "${subme} abc ${subme}"
)

$ for i in "${test[@]}"; do echo $i; done
its a test
for
123 abc 123
$

Cheers,

gglq000 · 06-10-2016, 10:55 AM

thanks, so single and double quotes differ in linux shell huh.
in my case, perils of using python where single and double quotes are same.