116

How can I iterate through all the local branches in my repository using bash script. I need to iterate and check is there any difference between the branch and some remote branches. Ex

for branch in $(git branch); 
do
    git log --oneline $branch ^remotes/origin/master;
done

I need to do something like given above, but the issue I'm facing is $(git branch) gives me the folders inside the repository folder along with the branches present in the repository.

Is this the correct way to solve this issue? Or is there another way to do it?

Thank you

Arun P Johny
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  • Possible duplicate of [for loop over all git branches with certain name](http://stackoverflow.com/questions/26724818/for-loop-over-all-git-branches-with-certain-name) – pihentagy Aug 24 '16 at 12:19
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    @pihentagy This was written before the linked question. – thefern Jul 01 '19 at 00:21
  • Eg: - `for b in "$(git branch)"; do git branch -D $b; done` – Abhi Jan 02 '20 at 07:39
  • Not a duplicate. This question goes for all branches while the other goes for ones with specific name – cincplug Feb 24 '21 at 08:28

13 Answers13

173

You should not use git branch when writing scripts. Git provides a “plumbing” interface that is explicitly designed for use in scripting (many current and historical implementations of normal Git commands (add, checkout, merge, etc.) use this same interface).

The plumbing command you want is git for-each-ref:

git for-each-ref --shell \
  --format='git log --oneline %(refname) ^origin/master' \
  refs/heads/

Note: You do not need the remotes/ prefix on the remote ref unless you have other refs that cause origin/master to match multiple places in the ref name search path (see “A symbolic ref name. …” in the Specifying Revisions section of git-rev-parse(1)). If you are trying to explictly avoid ambiguity, then go with the full ref name: refs/remotes/origin/master.

You will get output like this:

git log --oneline 'refs/heads/master' ^origin/master
git log --oneline 'refs/heads/other' ^origin/master
git log --oneline 'refs/heads/pu' ^origin/master

You can pipe this output into sh.

If you do not like the idea of generating the shell code, you could give up a bit of robustness* and do this:

for branch in $(git for-each-ref --format='%(refname)' refs/heads/); do
    git log --oneline "$branch" ^origin/master
done

* Ref names should be safe from the shell’s word splitting (see git-check-ref-format(1)). Personally I would stick with the former version (generated shell code); I am more confident that nothing inappropriate can happen with it.

Since you specified bash and it supports arrays, you could maintain safety and still avoid generating the guts of your loop:

branches=()
eval "$(git for-each-ref --shell --format='branches+=(%(refname))' refs/heads/)"
for branch in "${branches[@]}"; do
    # …
done

You could do something similar with $@ if you are not using a shell that supports arrays (set -- to initialize and set -- "$@" %(refname) to add elements).

finn
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Chris Johnsen
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    Seriously. There isn't a simpler way to do this? – Jim Fell Apr 17 '15 at 21:59
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    But what if I want to use one of the filtering options of git branch, like `--merged`, would I have to duplicate the logic in git branch? There has to be a better way to do this. – Thayne Apr 20 '15 at 21:23
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    Simplier version: `git for-each-ref refs/heads | cut -d/ -f3-` – wid Jan 13 '16 at 14:47
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    @wid: Or, simply, `git for-each-ref refs/heads --format='%(refname)'` – John Gietzen May 04 '16 at 19:30
  • If the output is safe from newlines, one can do this: `git for-each-ref --format='%(refname)' refs/heads | while read x ; do echo === $x === ; done`. Note that this puts the `while` loop into a subshell. If you want the `while` loop in the current shell, then this: `while read x ; do echo === $x === ; done < – Chris Cogdon Oct 23 '17 at 22:26
  • json needs to be used in command line tools, I can't believe Git and others haven't done this yet – Alexander Mills Aug 05 '18 at 18:02
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    @Thayne: this question is old, but the Git folks have finally addressed the problem: `for-each-ref` now supports all the branch selectors like `--merged` and `git branch` and `git tag` are now actually implemented in terms of `git for-each-ref` itself, at least for the list-existing cases. (Creating new branches and tags is not, and should not be, part of `for-each-ref`.) – torek Aug 05 '18 at 19:13
50

This is because git branch marks the current branch with an asterisk, e.g.:

$ git branch
* master
  mybranch
$ 

so $(git branch) expands to e.g. * master mybranch, and then the * expands to the list of files in the current directory.

I don't see an obvious option for not printing the asterisk in the first place; but you could chop it off:

$(git branch | cut -c 3-)
Matthew Slattery
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14

The bash builtin, mapfile, is built for this

all git branches: git branch --all --format='%(refname:short)'

all local git branches: git branch --format='%(refname:short)'

all remote git branches: git branch --remotes --format='%(refname:short)'

iterate through all git branches: mapfile -t -C my_callback -c 1 < <( get_branches )

example:

my_callback () {
  INDEX=${1}
  BRANCH=${2}
  echo "${INDEX} ${BRANCH}"
}
get_branches () {
  git branch --all --format='%(refname:short)'
}
# mapfile -t -C my_callback -c 1 BRANCHES < <( get_branches ) # if you want the branches that were sent to mapfile in a new array as well
# echo "${BRANCHES[@]}"
mapfile -t -C my_callback -c 1 < <( get_branches )

for the OP's specific situation:

#!/usr/bin/env bash


_map () {
  ARRAY=${1?}
  CALLBACK=${2?}
  mapfile -t -C "${CALLBACK}" -c 1 <<< "${ARRAY[@]}"
}


get_history_differences () {
  REF1=${1?}
  REF2=${2?}
  shift
  shift
  git log --oneline "${REF1}" ^"${REF2}" "${@}"
}


has_different_history () {
  REF1=${1?}
  REF2=${2?}
  HIST_DIFF=$( get_history_differences "${REF1}" "${REF2}" )
  return $( test -n "${HIST_DIFF}" )
}


print_different_branches () {
  read -r -a ARGS <<< "${@}"
  LOCAL=${ARGS[-1]?}
  for REMOTE in "${SOME_REMOTE_BRANCHES[@]}"; do
    if has_different_history "${LOCAL}" "${REMOTE}"; then
      # { echo; echo; get_history_differences "${LOCAL}" "${REMOTE}" --color=always; } # show differences
      echo local branch "${LOCAL}" is different than remote branch "${REMOTE}";
    fi
  done
}


get_local_branches () {
  git branch --format='%(refname:short)'
}


get_different_branches () {
  _map "$( get_local_branches )" print_different_branches
}


# read -r -a SOME_REMOTE_BRANCHES <<< "${@}" # use this instead for command line input
declare -a SOME_REMOTE_BRANCHES
SOME_REMOTE_BRANCHES=( origin/master remotes/origin/another-branch another-remote/another-interesting-branch )
DIFFERENT_BRANCHES=$( get_different_branches )

echo "${DIFFERENT_BRANCHES}"

source: List all local git branches without an asterisk

Andrew Miller
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6

I iterate as it for example :

for BRANCH in `git branch --list|sed 's/\*//g'`;
  do 
    git checkout $BRANCH
    git fetch
    git branch --set-upstream-to=origin/$BRANCH $BRANCH
  done
git checkout master;
Djory Krache
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4

I would suggest $(git branch|grep -o "[0-9A-Za-z]\+") if your local branches are named by digits, a-z, and/or A-Z letters only

4

The accepted answer is correct and really should be the approach used, but solving the problem in bash is a great exercise in understanding how shells work. The trick to doing this using bash without performing additional text manipulation, is to ensure the output of git branch never gets expanded as part of a command to be executed by the shell. This prevents the asterisk from ever being expanding in the file name expansion (step 8) of shell expansion (see http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_03_04.html)

Use the bash while construct with a read command to chop the git branch output into lines. The '*' will be read in as a literal character. Use a case statement to match it, paying special attention to the matching patterns.

git branch | while read line ; do                                                                                                        
    case $line in
        \*\ *) branch=${line#\*\ } ;;  # match the current branch
        *) branch=$line ;;             # match all the other branches
    esac
    git log --oneline $branch ^remotes/origin/master
done

The asterisks in both the bash case construct and in the parameter substitution need to be escaped with backslashes to prevent the shell interpreting them as pattern matching characters. The spaces are also escaped (to prevent tokenization) because you are literally matching '* '.

BitByteDog
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4

Easiest option to remember in my opinion:

git branch | grep "[^* ]+" -Eo

Output:

bamboo
develop
master

Grep's -o option (--only-matching) restricts the output to only the matching parts of the input.

Since neither space nor * are valid in Git branch names, this returns the list of branches without the extra characters.

Edit: If you're in 'detached head' state, you'll need to filter out the current entry:

git branch --list | grep -v "HEAD detached" | grep "[^* ]+" -oE

staafl
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3

What I ended up doing, applied to your question (& inspired by ccpizza mentioning tr):

git branch | tr -d ' *' | while IFS='' read -r line; do git log --oneline "$line" ^remotes/origin/master; done

(I use while loops a lot. While for particular things you'd definitely want to use a pointed variable name ["branch", for example], most of the time I am only concerned with doing something with each line of input. Using 'line' here instead of 'branch' is a nod to reusability/muscle memory/efficiency.)

Jan Kyu Peblik
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2

If you're at this state:

git branch -a

* master

  remotes/origin/HEAD -> origin/master

  remotes/origin/branch1

  remotes/origin/branch2

  remotes/origin/branch3

  remotes/origin/master

And you run this code:

git branch -a | grep remotes/origin/*

for BRANCH in `git branch -a | grep remotes/origin/*` ;

do
    A="$(cut -d'/' -f3 <<<"$BRANCH")"
    echo $A

done        

You'll get this result:

branch1

branch2

branch3

master
Christian Mann
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2
for branch in "$(git for-each-ref --format='%(refname:short)' refs/heads)"; do
    ...
done

This uses git plumbing commands, which are designed for scripting. It's also simple and standard.

Reference: Git's Bash completion

aude
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1

Extending on from @finn's answer (thank you!), the following will let you iterate over the branches without creating an intervening shell script. It's robust enough, as long as there's no newlines in the branch name :)

git for-each-ref --format='%(refname)' refs/heads  | while read x ; do echo === $x === ; done

The while loop runs in a subshell, which is usually fine unless you're setting shell variables that you want to access in the current shell. In that case you use process substitution to reverse the pipe:

while read x ; do echo === $x === ; done < <( git for-each-ref --format='%(refname)' refs/heads )
Chris Cogdon
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1

Keep it simple

The simple way of getting branch name in loop using bash script.

#!/bin/bash

for branch in $(git for-each-ref --format='%(refname)' refs/heads/); do
    echo "${branch/'refs/heads/'/''}" 
done

Output:

master
other
Googlian
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1

Googlian's answer, but without using for

git for-each-ref --format='%(refname:lstrip=-1)' refs/heads/
Master Yoda
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    This doesn't work for namespaced branch names, as in branches that have a slash in them. This means that branches created by dependabot, which look something like "dependabot/npm_and_yarn/typescript-3.9.5", will appear instead as "typescript-3.9.5". – ecbrodie Jun 23 '20 at 21:45