Retrieve single file from remote repository with git.

gistfile1.sh

git archive --remote {remote repository} {branch name/tree-ish} {file path} | tar -x --strip-components={directory depth}

gistfile2.sh

# Use any of the following commands if the tar command does not support --strip-components
 git archive --remote {remote repository} {branch name/tree-ish} {file path} | tar -x --strip-path={directory depth}
(git archive --remote {remote repository} {branch name/tree-ish} {file path} | tar -x -O ) > {file name}