bash script for updating all repositories, located in folder. Save as `your_name.sh` and add execution rights (`chmod +x your_name.sh`)

your_git_updater.sh

#!/bin/sh

for D in *; do
    if [ -d "${D}" ]; then
        cd "${D}"
        if [ -d ".git" ]; then
                git pull -v
        fi
        cd ..
    fi
done

Possible improvement if use next for understanding branch state

#!/bin/sh

UPSTREAM=${1:-'@{u}'}
LOCAL=$(git rev-parse @)
REMOTE=$(git rev-parse "$UPSTREAM")
BASE=$(git merge-base @ "$UPSTREAM")

if [ $LOCAL = $REMOTE ]; then
    echo "Up-to-date"
elif [ $LOCAL = $BASE ]; then
    echo "Need to pull"
elif [ $REMOTE = $BASE ]; then
    echo "Need to push"
else
    echo "Diverged"
fi