Run a git command on all repos in a directory tree.

dogit.sh

#!/bin/bash

function help {
    local dogit="$1"
    local lines=(
        "$dogit: Run a git command on all repos in a directory tree."
        ""
        "Usage: $dogit <directory> [<command> ...]"
        ""
        "Where: <directory> is the root of a tree of git repos."
        "       <command>   is some git command verb such as 'pull'."
        "       ...         is 0 or more arguments to <command>."
        ""
        "Example: Fetch all repos in and under the current directory."
        ""
        "         # $dogit . fetch -v"
        ""
        "Note: $dogit depends on a repo containing a '.git' directory"
        "      at its root, so it skips what are called 'bare' repos."
        "      Put your bare repos somewhere else -- like a git server."
        "      $dogit uses whatever 'git' command it finds in your path.")
    for line in "${lines[@]}"
    do
        echo "$line" 1>&2
    done
}

dogit="${0##*/}"
directory="$1"
shift
test -z "$directory" && help "$dogit" && exit 1
find "$directory" -type d -name '.git' -print |
    while read git
    do
        cd "$git/.."
        echo $dogit: In ${git%/.git} 1>&2
        git "$@"
        cd -
    done