How to split the output and store it in an array?

Question

This is the output:

3,aac-lc, 93.8, aaclc, 77.3, h.264, 1024.6, h.264, 1029.1, 31, 31, 0,0,0.000000,31,31,0,0,0.000000,7,0,0,0.000000,30,1280 720,10,0,0,0.000000,30,1280 720

I tried with 2 scenario:

1. Storing in an array

     @arr=split(',',$stats);
     echo "statistics: $stats"
   

2. Storing in a variable

    echo $stats | cut -d ',' -f | read s1
    echo $s1
   

But neither scenario is working.

Answer 1

You can use something like this, for a single line of input:

IFS="," read -ra arr <<< "$foo"

Demo:

$ cat t.sh 
foo="3,aac-lc, 93.8, aaclc, 77.3, h.264, 1024.6, ..." # snipped

IFS="," read -ra arr <<< "$foo"
echo ${#arr[@]}
echo ${arr[0]}
echo ${arr[30]}
$ ./t.sh 
31
3
1280 720

Credits: Split string based on delimiter in bash? answer by Johannes Schaub. Check the other answers there too.

Answer 2

$ set -f  # turn off globbing, so as not to expand wildcards
$ arr=($(echo "$stats" | sed 's/,/ /g'))
$ echo ${arr[1]}
aac-lc

Answer 3

Your first snippet is nothing like shell syntax. It is correct Perl syntax.
Your second snippet doesn't use cut correctly; I don't know what you intended.

The shell has a built-in string splitting construct: when you write $somevar without any quotes, the shell first looks up the value of the variable somevar, then splits that value into separate words on the characters specified by IFS, and finally interprets each word as a glob pattern (file wildcard). So you can split a string by setting IFS to the separator character and temporarily turning off globbing.

set -f; IFS=,
arr=($stats)
set +f; unset IFS

Note that if a field contains whitespace, the array element will retain that whitespace. If you want to split at all whitespace as well as commas, set IFS=', '. Note that IFS is not a string to split at but a set of characters to split at; either a space or a comma will constitute a separator. Furthermore, there are special rules for whitespace: any sequence of zero or more spaces followed by a comma followed by zero or more spaces will constitute one separator, and any sequence of one or more spaces will also constitute a separator.

If you only want to strip whitespace at the beginning or end of a field, you'll have to do it element by element.

shopt -s extglob
for ((i=0; i<${#arr[@]}; i++)); do
  arr[i]=${arr[i]#+( )}   # strip one or more spaces at the beginning
  arr[i]=${arr[i]%+( )}   # strip one or more spaces at the end
done