Script to run `git pull` inside all subdirectories which are git repositories. For Windows, macOS and Linux.

git-pull.bat

:: Script to run `git pull` inside all subdirectories which are git repositories.
:: usage 1: keep local changes, then up to date.
::   > git-pull.bat
:: usage 2: abort local changes, reset if possible, then up to date.
::   > git-pull.bat --force --no-stash
:: usage 3: try keep local changes, reset if possible, then up to date.
::   > git-pull.bat --force

@echo off

setlocal
:parse
    IF "%~1"=="" GOTO endparse
    IF "%~1"=="--force" set _FORCE=true
    IF "%~1"=="--no-stash" set _NO_STASH=true
    SHIFT
    GOTO parse
:endparse

for /f "tokens=* delims=" %%i in ('dir /ad /b "."') do (
    echo --- Working on %cd%\%%i
    pushd "%cd%\%%i"
        if NOT EXIST ".git\" (
            echo   x: \"%cd%\%%i\" is not a git repository, continue next directory.
        ) else (
            if not "%_NO_STASH%"=="true" ( git stash --quiet )
            if "%_FORCE%"=="true" ( git reset --hard )
            git pull
            if not "%_NO_STASH%"=="true" ( git stash apply --quiet )
        )
    popd
)

endlocal

git-pull.ps1

# Script to run `git pull` inside all subdirectories which are git repositories.
# usage 1: keep local changes, then up to date.
#   PS> ./git-pull.ps1
# usage 2: abort local changes, reset if possible, then up to date.
#   PS> ./git-pull.ps1 -Force -NoStash
# usage 3: try keep local changes, reset if possible, then up to date.
#   PS> ./git-pull.ps1 -Force

param(
    [Switch]$Force,
    [Switch]$NoStash
)

foreach ($dir in Get-ChildItem -Directory) {
    try {
        pushd $dir.FullName
            echo "--- Working on ""$($dir.FullName)"""

            if ((Get-ChildItem -Force -Directory).Name -notcontains ".git") {
                echo "  x: ""$($dir.FullName)"" is not a git repository, continue next directory."
                continue
            }

            if (!$NoStash) { git stash --quiet }
            if ($Force) { git reset --hard }
            git pull
            if (!$NoStash) { git stash apply --quiet }
    } finally {
        popd
    }
}

git-pull.sh

#!/bin/bash
set -o pipefail

# Script to run `git pull` inside all subdirectories which are git repositories.
# usage 1: keep local changes, then up to date.
#   $ bash ./git-pull.sh
# usage 2: abort local changes, reset if possible, then up to date.
#   $ bash ./git-pull.sh --force --no-stash
# usage 3: try keep local changes, reset if possible, then up to date.
#   $ bash ./git-pull.sh --force

while [ $# -gt 0 ]; do
    case $1 in
        --force) _FORCE=true; shift 1; ;;
        --no-stash) _NO_STASH=true; shift 1; ;;
        *) shift ;;
    esac
done

## find is not a good way to control. Additionally, this include CURRENT directory and it is unexpected.
# find . -maxdepth 1 -type d -exec bash -c 'echo "Working on $(realpath $1)"; git reset --force; git pull' shell {} \;

for dir in ./*/; do
    echo "--- Working on \"$(realpath "${dir}")\""
    pushd "$(realpath "${dir}")" > /dev/null
        if [[ ! -d ".git" ]]; then
            echo "  x: \"$(realpath "${dir}")\" is not a git repository, continue next directory."
            popd > /dev/null
            continue
        fi
        if [[ "${_NO_STASH:=false}" != "true" ]]; then git stash --quiet; fi
        if [[ "${_FORCE:=false}" == "true" ]]; then git reset --hard; fi
        git pull
        if [[ "${_NO_STASH:=false}" != "true" ]]; then git stash apply --quiet; fi
    popd > /dev/null
done

similar one: https://gist.github.com/phette23/7620214

added --no-stash option.