Unary operator expected

jnojr · 10-18-2012, 02:51 PM

In all my Googling, this usually happens when someone is comparing a variable, and that variable is unset. That doesn't appear to be the case for me...

Code:

#!/bin/bash -x

  while read line
  do
    f=$(echo $line | tr -s ' ' | cut -d' ' -f 3)
    echo $f
    if [ "$f" >= 500 ]
    then
      echo "This is a finding"
      echo $i
    fi
  done < /tmp/ls.txt

Result:

Code:

+ read line
++ echo drwxr-xr-x@ 39 0 0 1326 Oct 1 14:01 .
++ tr -s ' '
++ cut '-d ' -f 3
+ f=0
+ echo 0
0
+ '[' 0 500 ']'
./test.sh: line 15: [: 0: unary operator expected

It seems to be tossing my ">=" away.

millgates · 10-18-2012, 04:20 PM

I think bash does not like the >= operator inside brackets. It should be

Code:

if [ "$f" -ge 500 ]

or, slightly better

Code:

if [[ "$f" -ge 500 ]]

or, even better

Code:

if (( f >= 500 ))