Bracket missing error in simple bash line?

Question

The following 2 lines in my bash script:

fail_str=$\'Checking...\\nChecking...\'
if [ tail -1 /home/pi/video_buffer_usage.txt | grep \'100% full\' ] || [ tail -2         


        

Answer 1

lose the []s:

if tail -1 /home/pi/video_buffer_usage.txt | grep '100% full' ||
  tail -2 "$out_file" | grep "$fail_str" ; then

(added harmless newline for readability)

you may also then want to silence the greps:

if tail -1 /home/pi/video_buffer_usage.txt | grep -q '100% full' ||
  tail -2 "$out_file" | grep -q "$fail_str" ; then