tarball-and-sha256sum.sh

#!/usr/bin/env bash

# Using gnu tar, make a tarball using pax format and drop unneeded metadata
# Also sha256sum all files before creating the tarball and include a text file of checksums in the tarball.
#     Ref: https://www.gnu.org/software/tar/manual/html_chapter/Formats.html#Reproducibility
# Note that we delete mtime instead of setting it as the docs suggest above
# Note that gzip you may want --no-names; zstd has the same option, but it is enabled by default.
# Note that BSD tar (including mac os flavor) does not accept some of these options.
#
# License: CC0 v1.0 universal: https://creativecommons.org/publicdomain/zero/1.0/legalcode.txt

set -u


if [ "$#" -lt 2 ]; then
  echo "At least two arguments are required. Output tar archive, followed by items to archive."
  return 1
fi


BASENAME=$(basename -s ".tar" "$1")
SHAFILE="$BASENAME.sha256sums.txt"

for i in "${@:2}"; do
  # Checksum all files in all directories to be archived
  if [[ -d "$i" ]]; then
    find "$i" -type f -exec sha256sum {} \; >> "$SHAFILE"
  # Checksum all top-level files to be archive
  elif [[ -f "$i" ]]; then
    sha256sum "$i" >> "$SHAFILE"
  fi
done


LC_ALL=C tar --sort=name --format=posix                \
  --pax-option=exthdr.name=%d/PaxHeaders/%f            \
  --pax-option=delete=atime,delete=ctime,delete=mtime  \
  --numeric-owner --owner=0 --group=0                  \
  --mode=go+u,go-w                                     \
  -cvf "$1" "${@:2}" "$SHAFILE"

tarball.sh

#!/usr/bin/env bash

# Using gnu tar, make a tarball using pax format and drop unneeded metadata 
#
# Ref: https://www.gnu.org/software/tar/manual/html_chapter/Formats.html#Reproducibility
#
# Note that we delete mtime instead of setting it as the docs suggest above
# Note that gzip you may want --no-names; zstd has the same option, but it is enabled by default.
# Note that BSD tar (including mac os flavor) does not accept some of these options.
#
# License: CC0 v1.0 universal: https://creativecommons.org/publicdomain/zero/1.0/legalcode.txt

set -eu

if [ "$#" -lt 2 ]; then
  echo "At least two arguments are required. Output tar archive, followed by items to archive."
  return 1
fi

LC_ALL=C tar --sort=name --format=posix                  \
    --pax-option=exthdr.name=%d/PaxHeaders/%f            \
    --pax-option=delete=atime,delete=ctime,delete=mtime  \
    --numeric-owner --owner=0 --group=0                  \
    --mode=go+u,go-w                                     \
    -cvf "$1" "${@:2}"