Reset all branches of a local repo to be the same as remote

First this is different because this is for all branches not one

You can use a script which which will loop over your branches and then do what ever you want on each one:

# Loop on all the desired branches
for ref in $(git branch -a)
do
   # ... DO ANYTHING YOU NEED HERE
   # You have the $ref which stores the branch name
   # ex: remotes/origin/master
done

---

Is there a better ans simple solution?

Yes, simply clone the project again and you will have the same content as your origin.
This is exactly what you do manually per branch.

---

Note:

You can fetch all the data at once using this command:

# Fetch all remotes, branches and remove deledted content
git fetch --all --prune

Just wrote a small tool that does this.

Advantages of this tool:

1. Supports multiple remotes in one repository.
2. Supports having different names for the local and tracking branches.
3. No error-prone regex parsing/editing.

Here's the script:

#!/bin/bash

ENOENT=2
EEXIST=17

curref=$(git symbolic-ref HEAD 2>&-)

fetch_all() {
  git fetch --all
  ret=$?
  [ "$ret" -eq 0 ] || {
    return "$ret"
  }
}

hard_reset_all() {
  ret=0

  while read -r line; do
    branch=$(echo "$line" | cut -c 8- | rev | cut -c 8- | rev)
    remote=$(git config --local --get "branch.$branch.remote")
    upstream=$(git config --local --get "branch.$branch.merge" | cut -c 12-)

    if ! git rev-parse --verify --quiet "$remote/$upstream" 1>&- 2>&-; then
      ret=$(( $ret | $ENOENT ))
      echo "Branch $branch"
      echo "  skipped: upstream is absent"
      continue
    fi

    if [ -z "$(git log --oneline -1 "$branch...$remote/$upstream")" ]; then
      continue
    fi

    echo "Branch $branch"

    echo "  $(git log --oneline -1 $branch)"
    if [ "refs/heads/$branch" = "$curref" ]; then
      git reset --hard "$remote/$upstream" 1>&- 2>&-
    else
      git update-ref "refs/heads/$branch" "$remote/$upstream" 1>&- 2>&-
    fi
    echo "  -> $(git log --oneline -1 $remote/$upstream)"
  done < <(git config --local --name-only --get-regex '^branch.*remote$')

  return "$ret"
}

fetch_all
excode=$?
[ "$excode" -eq 0 ] || {
  exit "$excode"
}

if output=$(git status --porcelain) && [ -n "$output" ]; then
  echo "Skipped: repo is not clean"
  exit $EEXIST
fi

hard_reset_all
excode=$?
[ "$excode" -eq 0 ] || {
  exit "$excode"
}

Why not just delete all local branches, and then whenever a remote branch gets re-checked-out, you'll be synced?

 # BE CAREFUL!!!
 # THIS COMMAND WIPES OUT ALL LOCAL BRANCHES
 ​git branch | xargs git branch -D

xargs runs the provided command against every line of stdin, in this case "git branch -D" against every line of the original "git branch" command.

The "git branch -D" command will fail for current branch, but every other branch will get wiped.

Alternatively you could cook something up with "xargs" that runs "git branch -f" to force-set every local branch to its remote copy, but I think the "git branch -D" approach above is the simplest, and also the most straight-forward as far as consequences, potential hazards are concerned.