Issues with storing an echo of a date conversion into a string variable inunix

Question

Apologies but this question comes from a question previously raised: How can I convert a local date-time into UTC date-time? Toby has been absolutely great helping me with some conversion string-->BST -->GMT but ow i am facing another i believe dummy issue.

my .sh is simple:

# variables needed for testing
DateNew="20150903"
TimeNew="200001"

# concatenating date and time 
DateTimeNew_Suffix=${DateNew}${TimeNew}

# storing the conversion provided by Toby Speight into a variable
newPrefix=`echo "${DateTimeNew_Suffix}"| sed -re 's/^([0-9]{8})([0-9]{2})([0-9]{2})([0-9]{2})$/\1\\ \2:\3:\4/'| xargs date +@%s -d | xargs date -u +%Y%m%d%H%M%S -d`

#printing that value
echo $newPrefix

expected would be: "20150903190001" which should be the value assigned as a String into $newPrefix however Unix itself is throwing this exception:

date: extra operand 20:00:01' Try date --help' for more information.

date: option requires an argument -- 'd' Try `date --help' for more

information.

Running the command on its own i get the output expected:

echo "20150903200001"    | sed -re 's/^([0-9]{8})([0-9]{2})([0-9]{2})([0-9]{2})$/\1\\ \2:\3:\4/'    | xargs date +@%s -d    | xargs date -u +%Y%m%d%H%M%S -d

20150903190001

how can I store this echo into the newPrefix variable as a string? it look like conversion date into the variable is failing but the echo is not.

any help?

Answer 1

Solution found :)

DateNew='20150903'
TimeNew='200001'
DateTimeNew_Suffix=${DateNew}${TimeNew}
newPrefix=$(sed -n 1p $filename | sed -re 's/^([0-9]{8})([0-9]{2})([0-9]{2})([0-9]{2})$/\1\\ \2:\3:\4/'| xargs date +@%s -d| xargs date -u +%Y%m%d%H%M%S -d)
echo $newPrefix
echo "$newPrefix"