Make sure the files are converted from CRLF to LF in the update window - is there any performance?

Question

There was a lot of discussion about the core.autocrlf and core.safecrlf functions in the current version and the next release. The question I have relates to an environment where developers are cloning from open storage.

During cloning, auto cross settings are activated. But since developers have full control over their clone, they can remove this autocrlf setting and continue.

• We can specify non-binary files in a .gitattributes file, but is there any other way for GIT to automatically determine if the file is a text or binary file?

• Is there a way how the update hook (fixing the hook is impossible, since developers can still remove it) that can be placed to make sure that files (with CRLF) are forced out of the Windows environment on a UNIX machine that hosts the bare repo is converted to UNIX EOL (LF) format?

• Will an update hook that scans every file for CRLF affect the performance of the push operation?

thank

Answer 1

• 1 / Git itself has a heuristic to determine if a file is binary or text (similar to istext )

• 2/gergap weblog ( 2010) .
  . ( ), :
  , , , push, () eol.

Git LF->CRLF Windows.
CRLF, Git , CRCRLF, . CRLF, , , CRLF LF. Git .

, , , .
.

• 3/ , 30 , .
  , : , .
  , : .

---

#!/bin/sh
#
# Author: Gerhard Gappmeier, ascolab GmbH
# This script is based on the update.sample in git/contrib/hooks.
# You are free to use this script for whatever you want.
#
# To enable this hook, rename this file to "update".
#

# --- Command line
refname="$1"
oldrev="$2"
newrev="$3"
#echo "COMMANDLINE: $*"

# --- Safety check
if [ -z "$GIT_DIR" ]; then
    echo "Don't run this script from the command line." >&2
    echo " (if you want, you could supply GIT_DIR then run" >&2
    echo "  $0 <ref> <oldrev> <newrev>)" >&2
    exit 1
fi

if [ -z "$refname" -o -z "$oldrev" -o -z "$newrev" ]; then
    echo "Usage: $0 <ref> <oldrev> <newrev>" >&2
    exit 1
fi

BINARAY_EXT="pdb dll exe png gif jpg"

# returns 1 if the given filename is a binary file
function IsBinary() 
{
    result=0
    for ext in $BINARAY_EXT; do
        if [ "$ext" = "${1#*.}" ]; then
            result=1
            break
        fi
    done

    return $result
}

# make temp paths
tmp=$(mktemp /tmp/git.update.XXXXXX)
log=$(mktemp /tmp/git.update.log.XXXXXX)    
tree=$(mktemp /tmp/git.diff-tree.XXXXXX)
ret=0

git diff-tree -r "$oldrev" "$newrev" > $tree
#echo
#echo diff-tree:
#cat $tree

# read $tree using the file descriptors
exec 3<&0
exec 0<$tree
while read old_mode new_mode old_sha1 new_sha1 status name
do
    # debug output
    #echo "old_mode=$old_mode new_mode=$new_mode old_sha1=$old_sha1 new_sha1=$new_sha1 status=$status name=$name"
    # skip lines showing parent commit
    test -z "$new_sha1" && continue
    # skip deletions
    [ "$new_sha1" = "0000000000000000000000000000000000000000" ] && continue

    # don't do a CRLF check for binary files
    IsBinary $tmp
    if [ $? -eq 1 ]; then
        continue # skip binary files
    fi

    # check for CRLF
    git cat-file blob $new_sha1 > $tmp
    RESULT=`grep -Pl '\r\n' $tmp`
    echo $RESULT
    if [ "$RESULT" = "$tmp" ]; then
        echo "###################################################################################################"
        echo "# '$name' contains CRLF! Dear Windows developer, please activate the GIT core.autocrlf feature,"
        echo "# or change the line endings to LF before trying to push."
        echo "# Use 'git config core.autocrlf true' to activate CRLF conversion."
        echo "# OR use 'git reset HEAD~1' to undo your last commit and fix the line endings."
        echo "###################################################################################################"
        ret=1
    fi
done
exec 0<&3
# --- Finished
exit $ret