git: create a single patch file with multiple commits

create_patch.sh

# last three commits 
git format-patch -3 --stdout > multi_commit.patch
# all commits that are in your branch and not in master into a single patch file multi_commit.patch
git format-patch --signoff master --stdout > multi_commit.patch
# create patches in the folder ~/output/directory/ for all commits that are in your branch and not in master
git format-patch -o ~/output/directory/ --signoff master

Hi,
Can you please let me know the use of "--stdout" here?

Execute git format-patch --help to see help. Here is description:

By default, each output file is numbered sequentially from 1, and uses the first line of the commit message (massaged for pathname safety) as the filename. With the --numbered-files option, the output file names will only be numbers, without the first line of the commit appended. The names of the output files are printed to standard output, unless the --stdout option is specified.

Hi,
Can you please let me know what is the solution for this below fatal message
$ git am Patches/0002-This-is-second-commit.patch
fatal: previous rebase directory .git/rebase-apply still exists but mbox given.

you din't applied or committer the first patch

applied

https://stackoverflow.com/questions/24121709/git-error-previous-rebase-directory-git-rebase-apply-still-exists-but-mbox-giv