Split output of command by columns using Bash?

One easy way is to add a pass of tr to squeeze any repeated field separators out:

$ ps | egrep 11383 | tr -s ' ' | cut -d ' ' -f 4

Please note that the tr -s ' ' option will not remove any single leading spaces. If your column is right-aligned (as with ps pid)...

$ ps h -o pid,user -C ssh,sshd | tr -s " "
 1543 root
19645 root
19731 root

Then cutting will result in a blank line for some of those fields if it is the first column:

$ <previous command> | cut -d ' ' -f1

19645
19731

Unless you precede it with a space, obviously

$ <command> | sed -e "s/.*/ &/" | tr -s " "

Now, for this particular case of pid numbers (not names), there is a function called pgrep:

$ pgrep ssh

Shell functions

However, in general it is actually still possible to use shell functions in a concise manner, because there is a neat thing about the read command:

$ <command> | while read a b; do echo $a; done

The first parameter to read, a, selects the first column, and if there is more, everything else will be put in b. As a result, you never need more variables than the number of your column +1.

So,

while read a b c d; do echo $c; done

will then output the 3rd column. As indicated in my comment...

A piped read will be executed in an environment that does not pass variables to the calling script.

out=$(ps whatever | { read a b c d; echo $c; })

arr=($(ps whatever | { read a b c d; echo $c $b; }))
echo ${arr[1]}     # will output 'b'`

The Array Solution

So we then end up with the answer by @frayser which is to use the shell variable IFS which defaults to a space, to split the string into an array. It only works in Bash though. Dash and Ash do not support it. I have had a really hard time splitting a string into components in a Busybox thing. It is easy enough to get a single component (e.g. using awk) and then to repeat that for every parameter you need. But then you end up repeatedly calling awk on the same line, or repeatedly using a read block with echo on the same line. Which is not efficient or pretty. So you end up splitting using ${name%% *} and so on. Makes you yearn for some Python skills because in fact shell scripting is not a lot of fun anymore if half or more of the features you are accustomed to, are gone. But you can assume that even python would not be installed on such a system, and it wasn't ;-).

I think the simplest way is to use awk. Example:

$ echo "11383 pts/1    00:00:00 bash" | awk '{ print $4; }'
bash