Make git automatically remove trailing whitespace before committing

Question

I m using git with my team and would like to remove whitespace changes from my diffs  logs  merges  etc  I m assuming that the easiest way to do this would be for git to automatically remove trailing whitespace  and other whitespace errors  from all commits as they are applied   I have tried to add the following to by    gitconfig file but it doesn t do anything when I commit  Maybe it s designed for something different  What s the solution    core      whitespace   trailing-space space-before-tab  apply      whitespace   fix   I m using ruby in case anyone has any ruby specific ideas  Automatic code formatting before committing would be the next step  but that s a hard problem and not really causing a big problem

User · Answer

You can trick Git into fixing the whitespace for you, by tricking Git into treating your changes as a patch. In contrast to the "pre-commit hook" solutions, these solutions add whitespace-fixing commands to Git.

Yes, these are hacks.

Robust solutions

The following Git aliases are taken from my ~/.gitconfig.

By "robust" I mean that these aliases run without error, doing the right thing, regardless of whether the tree or index are dirty. However, they don't work if an interactive git rebase -i is already in progress; see my ~/.gitconfig for additional checks if you care about this corner case, where the git add -e trick described at the end should work.

If you want to run them directly in the shell, without creating a Git alias, just copy and paste everything between the double quotes (assuming your shell is Bash like).

Fix the index but not the tree

The following fixws Git alias fixes all whitespace errors in the index, if any, but doesn't touch the tree:

# Logic:
#
# The 'git stash save' fails if the tree is clean (instead of
# creating an empty stash :P). So, we only 'stash' and 'pop' if
# the tree is dirty.
#
# The 'git rebase --whitespace=fix HEAD~' throws away the commit
# if it's empty, and adding '--keep-empty' prevents the whitespace
# from being fixed. So, we first check that the index is dirty.
#
# Also:
# - '(! git diff-index --quiet --cached HEAD)' is true (zero) if
#   the index is dirty
# - '(! git diff-files --quiet .)' is true if the tree is dirty
#
# The 'rebase --whitespace=fix' trick is from here:
# https://stackoverflow.com/a/19156679/470844
fixws = !"\
  if (! git diff-files --quiet .) && \
     (! git diff-index --quiet --cached HEAD) ; then \
    git commit -m FIXWS_SAVE_INDEX && \
    git stash save FIXWS_SAVE_TREE && \
    git rebase --whitespace=fix HEAD~ && \
    git stash pop && \
    git reset --soft HEAD~ ; \
  elif (! git diff-index --quiet --cached HEAD) ; then \
    git commit -m FIXWS_SAVE_INDEX && \
    git rebase --whitespace=fix HEAD~ && \
    git reset --soft HEAD~ ; \
  fi"

The idea is to run git fixws before git commit if you have whitespace errors in the index.

Fix the index and the tree

The following fixws-global-tree-and-index Git alias fixes all whitespace errors in the index and the tree, if any:

# The different cases are:
# - dirty tree and dirty index
# - dirty tree and clean index
# - clean tree and dirty index
#
# We have to consider separate cases because the 'git rebase
# --whitespace=fix' is not compatible with empty commits (adding
# '--keep-empty' makes Git not fix the whitespace :P).
fixws-global-tree-and-index = !"\
  if (! git diff-files --quiet .) && \
     (! git diff-index --quiet --cached HEAD) ; then \
    git commit -m FIXWS_SAVE_INDEX && \
    git add -u :/ && \
    git commit -m FIXWS_SAVE_TREE && \
    git rebase --whitespace=fix HEAD~2 && \
    git reset HEAD~ && \
    git reset --soft HEAD~ ; \
  elif (! git diff-files --quiet .) ; then \
    git add -u :/ && \
    git commit -m FIXWS_SAVE_TREE && \
    git rebase --whitespace=fix HEAD~ && \
    git reset HEAD~ ; \
  elif (! git diff-index --quiet --cached HEAD) ; then \
    git commit -m FIXWS_SAVE_INDEX && \
    git rebase --whitespace=fix HEAD~ && \
    git reset --soft HEAD~ ; \
  fi"

To also fix whitespace in unversioned files, do

git add --intent-to-add <unversioned files> && git fixws-global-tree-and-index

Simple but not robust solutions

These versions are easier to copy and paste, but they don't do the right thing if their side conditions are not met.

Fix the sub-tree rooted at the current directory (but resets the index if it's not empty)

Using git add -e to "edit" the patches with the identity editor ::

(export GIT_EDITOR=: && git -c apply.whitespace=fix add -ue .) && git checkout . && git reset

Fix and preserve the index (but fails if the tree is dirty or the index is empty)

git commit -m TEMP && git rebase --whitespace=fix HEAD~ && git reset --soft HEAD~

Fix the tree and the index (but resets the index if it's not empty)

git add -u :/ && git commit -m TEMP && git rebase --whitespace=fix HEAD~ && git reset HEAD~

Explanation of the `export GIT_EDITOR=: && git -c apply.whitespace=fix add -ue .` trick

Before I learned about the git rebase --whitespace=fix trick from this answer I was using the more complicated git add trick everywhere.

If we did it manually:

Set apply.whitespace to fix (you only have to do this once):
```
git config apply.whitespace fix
```
This tells Git to fix whitespace in patches.
Convince Git to treat your changes as a patch:
```
git add -up .
```
Hit a+enterto select all changes for each file. You'll get a warning about Git fixing your whitespace errors.
(git -c color.ui=auto diff at this point reveals that your non-indexed changes are exactly the whitespace errors).
Remove the whitespace errors from your working copy:
```
git checkout .
```
Bring back your changes (if you aren't ready to commit them):
```
git reset
```

The GIT_EDITOR=: means to use : as the editor, and as a command : is the identity.

User · Answer

Here is an ubuntu mac os x compatible version      bin sh      A git hook script to find and fix trailing whitespace   in your commits  Bypass it with the --no-verify option   to git-commit    if git-rev-parse --verify HEAD  gt  dev null 2 gt  amp 1   then   against HEAD else     Initial commit  diff against an empty tree object   against 4b825dc642cb6eb9a060e54bf8d69288fbee4904 fi   Find files with trailing whitespace for FILE in  exec git diff-index --check --cached  against --   sed      -  d     sed -r  s   0-9          gt   dev null 2 gt  amp 1    sed -E  s   0-9            uniq    do     Fix them     sed -i  s    space           FILE   gt   dev null 2 gt  amp 1    sed -i    -E  s    space           FILE     git add   FILE  done    Now we can commit exit   Have fun

User · Answer

I wrote this pre-commit hook  which only removes the trailing white-space from the lines which you ve changed added  since the previous suggestions tend to create unreadable commits if the target files have too much trailing white-space      bin sh  if git rev-parse --verify HEAD  gt  dev null 2 gt  amp 1   then    against HEAD else      Initial commit  diff against an empty tree object    against 4b825dc642cb6eb9a060e54bf8d69288fbee4904 fi  IFS      files   git diff-index --check --cached  against --   sed      -  d    perl -pe  s   0-9           uniq  for file in  files   do     diff   git diff --cached  file      if test    git config diff noprefix      true   then         prefix 0     else         prefix 1     fi     echo   diff    patch -R -p prefix     diff   echo   diff    perl -pe  s    t      if m            out   echo   diff    patch -p prefix -f -s -t -o -      if      -eq 0    then         echo   diff    patch -p prefix -f -t -s     fi     git add  file done

User · Answer

Please try my pre-commit hooks  it can auto detect trailing-whitespace and remove it  Thank you   it can work under GitBash windows   Mac OS X and Linux     Snapshot     git commit -am  test  auto remove trailing whitespace in foobar main m  auto remove trailing whitespace in foobar AppDelegate m   master 80c11fe  test 1 file changed  2 insertions     2 deletions -

User · Answer

To delete trailing whitespace at end of line in a file portably  use ed   test -s file  amp  amp     printf   s n  H   g    space      s      wq    ed -s file

User · Answer

On Mac OS  or  likely  any BSD   the sed command parameters have to be slightly different  Try this      bin sh  if git-rev-parse --verify HEAD  gt  dev null 2 gt  amp 1   then    against HEAD else      Initial commit  diff against an empty tree object    against 4b825dc642cb6eb9a060e54bf8d69288fbee4904 fi    Find files with trailing whitespace for FILE in  exec git diff-index --check --cached  against --   sed      -  d    sed -E  s   0-9           uniq    do       Fix them      sed -i    -E  s    space           FILE      git add   FILE  done   Save this file as  git hooks pre-commit -- or look for the one that s already there  and paste the bottom chunk somewhere inside it  And remember to chmod a x it too   Or for global use  via Git commit hooks - global settings  you can put it in  GIT PREFIX git-core templates hooks  where GIT PREFIX is  usr or  usr local or  usr share or  opt local share  and run git init inside your existing repos    According to git help init       Running git init in an existing repository is safe  It will not overwrite things that are already there  The primary reason for rerunning git init is to pick up newly added templates

User · Answer

I d rather leave this task to your favorite editor   Just set a command to remove trailing spaces when saving

User · Answer

I found a git pre-commit hook that removes trailing whitespace      bin sh  if git-rev-parse --verify HEAD  gt  dev null 2 gt  amp 1   then    against HEAD else      Initial commit  diff against an empty tree object    against 4b825dc642cb6eb9a060e54bf8d69288fbee4904 fi   Find files with trailing whitespace for FILE in  exec git diff-index --check --cached  against --   sed      -  d    sed -r  s   0-9           uniq    do      Fix them     sed -i  s    space           FILE     git add   FILE  done exit

User · Answer

the for-loop for files uses the  IFS shell variable  in the given script  filenames with a character in them that also is in the  IFS-variable will be seen as two different files in the for-loop  This script fixes it  multiline-mode modifier as given sed-manual doesn t seem to work by default on my ubuntu box  so i sought for a different implemenation and found this with an iterating label  essentially it will only start substitution on the last line of the file if i ve understood it correctly      bin sh      A git hook script to find and fix trailing whitespace   in your commits  Bypass it with the --no-verify option   to git-commit    if git rev-parse --verify HEAD  gt  dev null 2 gt  amp 1 then     against HEAD else       Initial commit  diff against an empty tree object     against 4b825dc642cb6eb9a060e54bf8d69288fbee4904 fi  SAVEIFS   IFS    only use new-line character as seperator  introduces EOL-bug  IFS       Find files with trailing whitespace for FILE in        git diff-index --check --cached  against --         sed      -  d            sed -r  s   0-9            sed -E  s   0-9                   uniq     do   replace whitespace-characters with nothing   if first execution of sed-command fails  try second one  MacOSx-version                sed -i   a N   ba s  n         FILE   gt   dev null 2 gt  amp 1                        sed -i    -E   a N   ba s  n         FILE                 amp  amp       re- add files that have been altered to git commit-tree     when change was a   space  -character  EOL EOF git-history becomes weird        git add   FILE  done   restore  IFS IFS   SAVEIFS     exit script with the exit-code of git s check for whitespace-characters exec git diff-index --check --cached  against --    1  sed-subsition pattern  How can I replace a newline   n  using sed

User · Answer

This doesn t remove whitespace automatically before a commit  but it is pretty easy to effect  I put the following perl script in a file named git-wsf  git whitespace fix  in a dir in  PATH so I can   git wsf   sh  and it removes all whitespace only from lines of files that git reports as a diff       bin sh git diff --check   perl -x  0 exit      usr bin perl  use strict   my  stuff  while   lt  gt         if   trailing whitespace              my   file  line    split               push    stuff  file    line           while  my   file   line    each  stuff        printf  ex  s  lt  lt EOT n    file      for    line            printf   ds          n                 print  wq nEOT n

User · Answer

For Sublime Text users   Set following properly in you Setting-User configuration    trim trailing white space on save   true

User · Answer

Was thinking about this today  This is all I ended up doing for a java project    egrep -rl      --include   java      xargs sed -i  s  s     g

User · Answer

Using git attributes  and filters setup with git config  OK  this is a new tack on solving this problem    My approach is to not use any hooks  but rather use filters and git attributes  What this allows you to do  is setup  on each machine you develop on  a set of filters that will strip extra trailing white space and extra blank lines at the end of files before committing them  Then setup a  gitattributes file that says which types of files the filter should be applied to  The filters have two phases  clean which is applied when adding files to the index  and smudge which is applied when adding them to the working directory   Tell your git to look for a global attributes file  First  tell your global config to use a global attributes file   git config --global core attributesfile    gitattributes global   Create global filters  Now  create the filter   git config --global filter fix-eol-eof clean fixup-eol-eof  f git config --global filter fix-eol-eof smudge cat git config --global filter fix-eol-eof required true   Add the sed scripting magic  Finally  put the fixup-eol-eof script somewhere on your path  and make it executable  The script uses sed to do some on the fly editing  remove spaces and blanks at the end of lines  and extraneous blank lines at the end of the file   fixup-eol-eof should look like this      bin bash sed -e  s           -e  a -e     n     d N ba  -e      1   my gist of this  Tell git which file types to apply your newly created filter to  Lastly  create or open    gitattributes global in your favorite editor and add lines like   pattern attr1  attr2  attr3           So if we want to fix the whitespace issue  for all of our c source files we would add a line that looks like this     c filter fix-eol-eof   Discussion of the filter  The filter has two phases  the clean phase which is applied when things are added to the index or checked in  and the smudge phase when git puts stuff into your working directory  Here  our smudge is just running the contents through the cat command which should leave them unchanged  with the exception of possibly adding a trailing newline character if there wasn   t one at the end of the file  The clean command is the whitespace filtering which I cobbled together from notes at http   sed sourceforge net sed1line txt  It seems that it must be put into a shell script  I couldn   t figure out how to inject the sed command  including the sanitation of the extraneous extra lines at the end of the file directly into the git-config file   You CAN get rid of trailing blanks  however  without the need of a separate sed script  just set the filter fix-eol-eofto something like sed  s    t        f where the  t is an actual tab  by pressing tab    The require   true causes an error to be raised if something goes wrong  to keep you out of trouble   Please forgive me if my language concerning git is imprecise  I think I have a fairly good grasp of the concepts but am still learning the terminology

User · Answer

This probably won t directly solve your problem  but you might want to set those via git-config in your actual project space  which edits    git config as opposed to    gitconfig   Nice to keep the settings consistent among all project members   git config core whitespace  trailing-space space-before-tab  git config apply whitespace  trailing-space space-before-tab

User · Answer

Those settings  core whitespace and apply whitespace  are not there to remove trailing whitespace but to    core whitespace  detect them  and raise errors  apply whitespace  and strip them  but only during patch  not  always automatically    I believe the git hook pre-commit would do a better job for that  includes removing trailing whitespace     Note that at any given time you can choose to not run  the pre-commit hook    temporarily  git commit --no-verify   permanently  cd  git hooks    chmod -x pre-commit   Warning  by default  a pre-commit script  like this one   has not a  remove trailing  feature   but a  warning  feature like   if    s          bad line  trailing whitespace            You could however build a better pre-commit hook  especially when you consider that      Committing in Git with only some changes added to the staging area still results in an    atomic    revision that may never have existed as a working copy and may not work      For instance  oldman proposes in another answer a pre-commit hook which detects and remove whitespace  Since that hook get the file name of each file  I would recommend to be careful for certain type of files  you don t want to remove trailing whitespace in  md  markdown  files

User · Answer

Slightly late but since this might help someone out there  here goes    Open the file in VIM  To replace tabs with whitespaces  type the following in vim command line    s  t      gc   To get rid of other trailing whitespaces    s  s  gc   This pretty much did it for me  It s tedious if you have a lot of files to edit  But I found it easier than pre-commit hooks and working with multiple editors

[git] Make git automatically remove trailing whitespace before committing

Robust solutions

Fix the index but not the tree

Fix the index and the tree

Simple but not robust solutions

Fix the sub-tree rooted at the current directory (but resets the index if it's not empty)

Fix and preserve the index (but fails if the tree is dirty or the index is empty)

Fix the tree and the index (but resets the index if it's not empty)

Explanation of the `export GIT_EDITOR=: && git -c apply.whitespace=fix add -ue .` trick

Examples related to git

Examples related to whitespace

Examples related to githooks

[git] Make git automatically remove trailing whitespace before committing

Robust solutions

Fix the index but not the tree

Fix the index and the tree

Simple but not robust solutions

Fix the sub-tree rooted at the current directory (but resets the index if it's not empty)

Fix and preserve the index (but fails if the tree is dirty or the index is empty)

Fix the tree and the index (but resets the index if it's not empty)

Explanation of the export GIT_EDITOR=: && git -c apply.whitespace=fix add -ue . trick

Examples related to git

Examples related to whitespace

Examples related to githooks

Explanation of the `export GIT_EDITOR=: && git -c apply.whitespace=fix add -ue .` trick