bin/sh script fails with syntax error: unexpected redirection

Question

I have the following bash script I'm now trying to convert to run using the system shell instead:

  1 #!/bin/sh
  2 #testtotal
  3 lines="$(crontab -l | awk '{if(NR>2)print}')"
  4 echo "1..$lines"
  5 counter=1
  6 while read p; do
  7         if [[ -x "$p" ]]
  8         then
  9             echo "ok $counter - $p is executable"
 10         else
 11             echo "not ok $counter - $p is not executable or found"
 12         fi
 13         counter=$((counter+1))
 14 done < <(crontab -l | awk '{if(NR>2)print}' | awk '{print $6}')

when I run using "sh" it fails with the error:

      ctest: line 14: syntax error: unexpected redirection 

Can you tell me how to adapt this to run under bin/sh?

Answer 1

On line 7, instead of [[ ... ]] you want [ ... ] or test ... (making sure to always, always, always quote every variable -- which you've already done, but with [ it's not optional and it's worth repeating for everyone else reading).

if [ -x "$p" ]

On line 14, you can use a here-document combined with a command substitution to replace the process substitution:

done <<EOF
$(crontab -l | awk 'NR > 2 { print $6 }')
EOF

This way you avoid running the while read p loop in a subshell due to piping into it, so your variables will survive.

That should do it to make this POSIX compliant.