Git pre-commit hook to find text in files

Question

I'm writing a git pre-commit hook to check if any of the staged files are containing disallowed text and abort if that's the case.

Not an expert at this. So far I've got this

git diff --cached --name-status | while read x file; do
        if [ "$x" == 'D' ]; then continue; fi
        if [[ egrep "DISALLOWED_TEXT" ${file}]]; then
                echo "ERROR: Disallowed text in file: ${file}"
                exit 1
        fi
done

Doesn't seem to work. I'm getting these errors while commiting:

.git/hooks/pre-commit: line 16: conditional binary operator expected
.git/hooks/pre-commit: line 16: syntax error near `"DISALLOWED_TEXT"'
.git/hooks/pre-commit: line 16: `        if [[ egrep "DISALLOWED_TEXT" ${file}]]; then'

Any suggestions, ideas and help appreciated. Thanks!

SOLVED: (syntax errors and dysfunctional exit call)

disallowed="word1 word2"

git diff --cached --name-status | while read x file; do
        if [ "$x" == 'D' ]; then continue; fi
        for word in $disallowed
        do
            if egrep $word $file ; then
                echo "ERROR: Disallowed expression \"${word}\" in file: ${file}"
                exit 1
            fi
        done
done || exit $?

Answer 1

Answer to mark this question as having an answer:

OP ended up with:

disallowed="word1 word2"

git diff --cached --name-status | while read x file; do
        if [ "$x" == 'D' ]; then continue; fi
        for word in $disallowed
        do
            if egrep $word $file ; then
                echo "ERROR: Disallowed expression \"${word}\" in file: ${file}"
                exit 1
            fi
        done
done || exit $?

Answer 2

I am using the same logic as above and even though the stagged file contains the disallowed word, it commits the changes to the branch. Any lead would be greatly appreciated.

#!/bin/bash
import os
echo "Running pre-commit hook" 
checks=os.environ["APPSETTING_DEVPASSWORD"],os.environ["APPSETTING_DEVUSER"],os.environ["APPSETTING_DEVPASS_ELMAH"]


git diff --cached --name-status | while read x file; do

          if [ "$x" == 'D' ]; then continue; fi
        for word in $checks
        do
            if egrep $word $file ; then
                echo "ERROR: Disallowed expression \"${word}\" in file: ${file}"
                exit 1
            fi
        done
done || exit $?