Question

I’m trying to write a script that will help me map some old users to new users in a handful of Git repositories. The problem I’m having is with the subprocess module. Simple commands like “git status” seem to work fine, but the more complex “git filter-branch” command is failing on me.

filter_history function

def filter_history(old, new, name, repoPath):

command = """ filter-branch --env-filter '
        an="$GIT_AUTHOR_NAME"
        am="$GIT_AUTHOR_EMAIL"
        cn="$GIT_COMMITTER_NAME"
        cm="$GIT_COMMITTER_EMAIL"

        if [[ "$GIT_COMMITTER_EMAIL" == |old|* ]]
        then
            cn="|name|"
            cm="|new|"
        fi
        if [[ "$GIT_AUTHOR_EMAIL" == |old|* ]]
        then
            an="|name|"
            am="|new|"
        fi

        export GIT_AUTHOR_NAME="$an"
        export GIT_AUTHOR_EMAIL="$am"
        export GIT_COMMITTER_NAME="$cn"
        export GIT_COMMITTER_EMAIL="$cm"
    '
"""

#Do string replace
command = command.replace("|old|", old)
command = command.replace("|new|", new)
command = command.replace("|name|", name)

subprocess.Popen(['/usr/bin/git', command], cwd=os.path.dirname(repoPath), shell=False)

Some example output:

fatal: cannot exec 'git- filter-branch --env-filter '
        an="$GIT_AUTHOR_NAME"
        am="$GIT_AUTHOR_EMAIL"
        cn="$GIT_COMMITTER_NAME"
        cm="$GIT_COMMITTER_EMAIL"

        if [[ "$GIT_COMMITTER_EMAIL" == jacks* ]]
        then
            cn="Jack Slingerland"
            cm="jacks-teamddm"
        fi
        if [[ "$GIT_AUTHOR_EMAIL" == jacks* ]]
        then
            an="Jack Slingerland"
            am="jacks-teamddm"
        fi

        export GIT_AUTHOR_NAME="$an"
        export GIT_AUTHOR_EMAIL="$am"
        export GIT_COMMITTER_NAME="$cn"
        export GIT_COMMITTER_EMAIL="$cm"
    '
': File name too long

Some things I’ve noticed are that the git command is getting a hyphen appended to it, which doesn’t make a ton of sense to me. Also, if I remove the extra hypen from the command that is printed and execute it in repoPath, everything works fine. Any help or direction on this would be greatly appreciated.

Answer 1

This should work: (I am using linux)

def filter_history(old, new, name, repoPath):
    command = """'
        an="$GIT_AUTHOR_NAME"
        am="$GIT_AUTHOR_EMAIL"
        cn="$GIT_COMMITTER_NAME"
        cm="$GIT_COMMITTER_EMAIL"

        if [[ "$GIT_COMMITTER_EMAIL" == |old|* ]]
        then
            cn="|name|"
            cm="|new|"
        fi
        if [[ "$GIT_AUTHOR_EMAIL" == |old|* ]]
        then
            an="|name|"
            am="|new|"
        fi

        export GIT_AUTHOR_NAME="$an"
        export GIT_AUTHOR_EMAIL="$am"
        export GIT_COMMITTER_NAME="$cn"
        export GIT_COMMITTER_EMAIL="$cm"
    '
    """

#Do string replace
    command = command.replace("|old|", old)
    command = command.replace("|new|", new)
    command = command.replace("|name|", name)

    subprocess.Popen(['git filter-branch --env-filter', command],cwd=os.path.dirname(repoPath), shell=True)

Note that “shell=True” in subprocess.Popen function