support/scripts/hardlink-or-copy

   1 #!/bin/bash
   2
   3 # Try to hardlink a file into a directory, fallback to copy on failure.
   4 #
   5 # Hardlink-or-copy the source file in the first argument into the
   6 # destination directory in the second argument, using the basename in
   7 # the third argument as basename for the destination file. If the third
   8 # argument is missing, use the basename of the source file as basename
   9 # for the destination file.
  10 #
  11 # In either case, remove the destination prior to doing the
  12 # hardlink-or-copy.
  13 #
  14 # Note that this is NOT an atomic operation.
  15
  16 set -e
  17
  18 main() {
  19     local src_file="${1}"
  20     local dst_dir="${2}"
  21     local dst_file="${3}"
  22
  23     if [ -n "${dst_file}" ]; then
  24         dst_file="${dst_dir}/${dst_file}"
  25     else
  26         dst_file="${dst_dir}/${src_file##*/}"
  27     fi
  28
  29     mkdir -p "${dst_dir}"
  30     rm -f "${dst_file}"
  31     ln -f "${src_file}" "${dst_file}" 2>/dev/null \
  32     || cp -f "${src_file}" "${dst_file}"
  33 }
  34
  35 main "${@}"