rename-recent

#!/usr/bin/env bash
set -euo pipefail
trap 'e=$?; [ $e -ne 0 ] && echo "$0 exited in error"' EXIT
env | grep ^DRYRUN= && DRYRUN=echo || DRYRUN=""
usage(){
 cat <<H
 USAGE:
  $(basename $0) rename_regexp outdir file_pattern  [rename options]

 EXAMPLE:
  rename-recent 's/_e\d+(_ph?)(.nii.gz|.json)$/\$2/' ../subjs/sub-11_2489_20201217/fmap/ '*phase*'

 SYNOPSIS:
  only works on .nii.gz, .json, and .nii files!

  use regular express "rename_regexp" (see 'rename --man')
  to rename files in "outdir"
  matching "file_pattern" (-iname "\$file_pattern")
  there were created in the last day (find -mtime -1)

  optionally give e.g. -n at the end for dryrun
  (options passed on to 'rename')

 ALT USAGE:
  $(basename $0) have?

  check that we have the right 'rename' command. print it if we do. error to STDERR otherwise

 NOTE:
  * some work is done to make sure perl-rename is being used instead of another rename utility
  * created for 'mknii'
H
  exit 1
}

find_rename(){
 # don't have admin access to make perl's rename the defacto
 #
 # if rename exists it could be as perl-rename or normal utils rename
 if command -v perl-rename >/dev/null; then 
   cmd="perl-rename"
 else
   cmd="$(which rename)"
 fi
 # perl's rename has "perl" in the man output
 # system name just prints "call: rename from to files..."
 # cannot use grep -q. $cmd --man might return failing status code
 [ -n "$($cmd --man 2>&1 | grep perl)" ] && echo $cmd && return 0
 echo "wrong/no 'rename' command ('$cmd') in \$PATH! try 'cpanm File::Rename' or rearrange PATH" >&2
 return 1
}

my_rename(){
 local cmd=$(find_rename)
 [ -z "$cmd" ] && exit 1
 # use it
 [ -n "$DRYRUN" ] && dr="-n" || dr=""
 $cmd $dr "$@";
}

main(){
  env|grep -q ^VERBOSE=. && set -x
  # just run "find_rename" -- for debugging and checking
  if [ $# -gt 0 ] && [ "$1" == "have?" ]; then
    find_rename
    exit $?
  fi

  [ $# -lt 3 ] && usage

  # rename using: replace pattern, outdir, file pattern
  # prev. used find|xargs rename. but working around old systems w/o admin access
  # using "my_rename"
  #   xargs -r rename 's/[12]?_e(\d.(nii.gz|json))$/$1/'
  #   xargs -r rename 's/_e\d+(_ph?)(.nii.gz|.json)$/$2/'
  local rename_regexp="$1"; shift
  local outdir="$1"; shift
  local pattern="$1"; shift
  [ $# -gt 0 ] && ARGS="$*" || ARGS=""  # allow -n to sneak in for dry run tests
  torename=( $(find $outdir -type f -mtime -1 -iname "$pattern" \
     \( -iname '*nii.gz' -or -iname '*json' -or -iname '*.nii' \))  )
  [ -n "$DRYRUN" ] && echo "# rename-recent top level: '$rename_regexp' for '$outdir/$pattern'" &&
                      echo "# have '${#torename[@]}' matches"

  for f in "${torename[@]}"; do
    my_rename $ARGS "$rename_regexp" "$f"
  done
}

[[ "$(caller)" != "0 "* ]] || main "$@"