arrays - Why is my bash shell script working on v 3.2.5 and failing on 4.1.2? -

my bash shell script working on bash 3.2.5. have input file contains following content:

1234567 2345678 3456789 4567890 

and bash shell script has following code:

#!/bin/bash content=($(cat data.txt | awk {'print $1'})) (( i=0 ; i<${#content[@]} ; i++ ))   if (( i==0 ))       ele=`echo ${content[$i]}`   else     ele=`echo ","${content[$i]}`   fi   all=`echo $all$ele` done # should string of csv: works on bash 3.2.5 - fails on bash 4.1.2 echo $all 

when run bash 3.2.5 outputs: (expected output; correct)

1234567,2345678,3456789,4567890 

but when run bash 4.1.2 outputs: (the last number in file; not correct)

,4567890 

why same code failing in bash 4.1.2?

using echo set contents of variable plain .. wrong. when wrong, mean, can it, there absolutely no reason use command substitution of echo statement fill variables in case. likewise, there no reason use cat piped awk fill array. filling array easier done simple redirection.

by eliminating unneeded command substitution of echo , piped commands, eliminate lot of opportunity error. here update work on either 3 or 4.

#!/bin/bash content=( $( <data.txt) ) (( i=0 ; i<${#content[@]} ; i++ ))     if (( i==0 ))             ele="${content[i]}"     else         ele=",${content[i]}"     fi     all="${all}${ele}" done echo $all 

output

$ bash bash34fail.sh 1234567,2345678,3456789,4567890