CODEWITHSUNDEEP
arraysbashfilecommandoutput
Arsene Lupen
Arsene Lupen

Reputation: 1

Fill in multiple arrays from command's output - Bash

I'm looking for the best way to fill in multiple arrays from command's output using Bash.

The solution I figured out at this stage is:

i=1
ls -al | while read line
do
            # Separate columns into arrays
            array_filetype[ $i ]=`echo $line | awk '{print $1}'`
            array_owner[ $i ]=`echo $line | awk '{print $3}'`
            array_group[ $i ]=`echo $line | awk '{print $4}'`
            echo "${array_filetype[$i]} - ${array_owner[$i]} - ${array_group[$i]}"
    (( i++ ))
done

The output is:

drwxrwxr-x - arsene - arsene
drwx--x--- - arsene - arsene
-rw-rw-r-- - arsene - arsene
-rw-rw-r-- - arsene - arsene
-rw-rw-r-- - arsene - arsene
-rw-rw-r-- - arsene - arsene
-rw-rw-r-- - arsene - arsene
-rwx------ - arsene - arsene
-rwx------ - arsene - arsene
-rwxr-xr-x - arsene - arsene
-rwx------ - root - root

Thanks in advance.

Arsene

Upvotes: 0

Views: 285

Answers (1)

lynxlynxlynx
lynxlynxlynx

Reputation: 1433

An immediate improvement that you can do is to not read the line as a whole:

i=1
ls -al | while read type links owner group rest-of-line-we-dont-care-about
do
     # Separate columns into arrays
     array_filetype[$i]=$type
     array_owner[$i]=$owner
     array_group[$i]=$group
     echo "${array_filetype[$i]} - ${array_owner[$i]} - ${array_group[$i]}"
    (( i++ ))
done

However, you will likely suddenly have it stop working once you want to use the arrays for more than just printing inside the loop. Since you're setting them in a subshell, the parent will not be affected. Here's one of the possible fixes:

i=1
while read type links owner group rest-of-line-we-dont-care-about
do
     # Separate columns into arrays
     array_filetype[$i]=$type
     array_owner[$i]=$owner
     array_group[$i]=$group
     echo "${array_filetype[$i]} - ${array_owner[$i]} - ${array_group[$i]}"
    (( i++ ))
done < <(ls -al)

Upvotes: 3

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