Split variable into multiple variables

Question

I understand this has been asked before but the answer don't quite give me what I need. I pgrep for a given string which returns a list of PID's containing that string in a variable ($testpid in this case). I then try and split each one of the PID's out, they are sepereated with a space like so:

PIDS:

17717 172132 2138213

Code:

IFS=" " read -a pidarray <<< "$testpid"
echo pidarray[0]

*instead of the echo above i would be assigning each item in the array to its own variable

But I get the following error:

syntax error: redirection unexpected

Answer 1

Your syntax was almost correct:

IFS=' ' read -r -a pidarray <<< "$testpid"
echo "${pidarray[0]}"

Note the curly braces needed for the array dereference.

More importantly, check that your shebang is #!/bin/bash, or that you executed your script with bash yourscript, not sh yourscript. The error given is consistent with a shell that doesn't recognize <<< as valid syntax -- which any remotely modern bash always will when invoked as bash; even if /bin/sh points to the same executable, it tells bash to disable many of its extensions from the POSIX spec.

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Now, that said -- if your goal is to assign each entry to its own variable, you don't need (and shouldn't use) read -a at all!

Instead:

IFS=' ' read -r first second third rest <<<"$testpid"
printf '%s\n' "First PID is $first" "Second PID is $second"