pre-commit hook to prevent binary check-ins

pre-commit.md

Navigate to hooks folder and make pre-commit script

cd ${GIT_REOP}/.git/hooks
cp pre-commit.sample pre-commit 

Add below code to pre-comit script

function checkForBinaries() {
    binaryFilesCount=0
    # echo "PWD: ${PWD}"
    for file in $(git diff --cached --name-only --diff-filter=d) ; do 
        binaryFlag=$(file --mime ${file} | grep binary)
        if [[ ! -z "${binaryFlag}" ]] ; then
            binaryFiles="${binaryFiles}\n$file"
            let binaryFilesCount+=1
        fi
    done

    if [[ ! -z "${binaryFiles}" && "${binaryFilesCount}" > 0 ]] ; then
        printf "\nFound below binary files: \n\t"
        printf "\033[33m${binaryFiles}\033[0m \n\n"
        printf "Please fix and continue. Fore more details look at .git/hooks/pre-commit\n"
        exit 1
    fi
}

checkForBinaries

Which makes the whole script looks like below.

Here is the whole pre-commit script

#!/usr/bin/env bash
#
# An example hook script to verify what is about to be committed.
# Called by "git commit" with no arguments.  The hook should
# exit with non-zero status after issuing an appropriate message if
# it wants to stop the commit.
#
# To enable this hook, rename this file to "pre-commit".
# printf "Pre-commit ... working\n"

function checkForBinaries() {
    binaryFilesCount=0
    # echo "PWD: ${PWD}"
    for file in $(git diff --cached --name-only --diff-filter=d) ; do 
        binaryFlag=$(file --mime ${file} | grep binary)
        if [[ ! -z "${binaryFlag}" ]] ; then
            binaryFiles="${binaryFiles}\n$file"
            let binaryFilesCount+=1
        fi
    done

    if [[ ! -z "${binaryFiles}" && "${binaryFilesCount}" > 0 ]] ; then
        printf "\nFound below binary files: \n\t"
        printf "\033[33m${binaryFiles}\033[0m \n\n"
        printf "Please fix and continue. Fore more details look at .git/hooks/pre-commit\n"
        exit 1
    fi
}

checkForBinaries


if git rev-parse --verify HEAD >/dev/null 2>&1
then
    against=HEAD
else
    # Initial commit: diff against an empty tree object
    against=$(git hash-object -t tree /dev/null)
fi

# If you want to allow non-ASCII filenames set this variable to true.
allownonascii=$(git config --bool hooks.allownonascii)

# Redirect output to stderr.
exec 1>&2


# Cross platform projects tend to avoid non-ASCII filenames; prevent
# them from being added to the repository. We exploit the fact that the
# printable range starts at the space character and ends with tilde.
if [ "$allownonascii" != "true" ] &&
    # Note that the use of brackets around a tr range is ok here, (it's
    # even required, for portability to Solaris 10's /usr/bin/tr), since
    # the square bracket bytes happen to fall in the designated range.
    test $(git diff --cached --name-only --diff-filter=A -z $against |
    LC_ALL=C tr -d '[ -~]\0' | wc -c) != 0
then
    cat <<\EOF
Error: Attempt to add a non-ASCII file name.

This can cause problems if you want to work with people on other platforms.

To be portable it is advisable to rename the file.

If you know what you are doing you can disable this check using:

git config hooks.allownonascii true
EOF
    exit 1
fi

# If there are whitespace errors, print the offending file names and fail.
# exec git diff-index --check --cached $against --