UNIX Script for a list of strings find those not in any file

Question

I'm parsing a properties file to get a list of properties defiend. I want to check all the places these properties are used (target dir and subdirs), flagging up any that are defined in the properties file but not used anywhere in the targer dir. Thus far I have

FILE=$1
TARGETROOT=$2

for LINE in `grep '[A-Z]*=' $FILE | awk -F '=' '{print$1}'`;
do

done;

Inside this loop I want to find those $LINE vars which are not in $TARGETROOT or its subdirs

Example files

Properties File
a=1
b=2
c=3
...

Many files that contain references to properties via

FILE 1
PropAValue = a

Answer 1

check the return code of grep.

You can do this by inspecting the $? variable.

if it is 0 then the string was found, otherwise the string was not found. If not 0 then add that string to a 'not found' array and that should be your list of not found properties.

grep "string" 
if [$? -ne 0] 
then 
   string not found 
fi

Answer 2

• Using xyz | while read PROP instead of for PROP in ``xyz``; do for those cases when xyz can get arbitrarily large

• Using grep -l ... >/dev/null || xyz to execute xyz if grep fails to match, and discard the grep output do /dev/null without executing xyz if one match is found (-l stops grep after the first match, if any, making it more efficient)

  FILE=$1 
  TARGETROOT=$2
  
  
  grep '^[A-Z]*=' "$FILE2" | awk -F= '{print$1}' | while read PROP ; do
    find "$TARGETROOT" -type f | while read FILE2 ; do
      grep -l "^${PROP}=" "$FILE2" >/dev/null || {
        echo "Propery $PROP missing from $FILE2"
      }
    done
  done
  

If dealing with a large number of properties and/or files under $TARGETROOT you can use the following, more efficient approach (which opens and scans each file only once instead of the previous solution's N times, where N was the number of properties in $FILE):

• Using a temporary file with all sorted properties from $FILE to avoid duplicating work
• Using awk ... | sort -u to isolate all sorted properties appearing in another file $FILE2

• Using comm -23 "$PROPSFILE" - to isolate those lines (properties) which only appear in $PROPSFILE and not on the standard input (i.e. in $FILE2)

  FILE=$1 
  TARGETROOT=$2
  
  
  PROPSFILE="/tmp/~props.$$"
  grep '^[A-Z]*=' "$FILE" | awk -F= '{print$1}' | sort -u >"$PROPSFILE"
  
  
  find "$TARGETROOT" -type f | while read FILE2 ; do
    grep '^[A-Z]*=' "$FILE2" | awk -F= '{print$1}' | sort -u |
    comm -23 "$PROPSFILE" - | while read PROP ; do
      echo "Propery $PROP missing from $FILE2"
    done
  done
  
  
  rm -f "$PROPSFILE"
  

Cheers, V.