Re: Reworking filenames

4 May 2017

      On 04/05/17 10:38, Tim Connors via luv-main wrote:
...
On Tue, 2 May 2017, Andrew McGlashan wrote:
...
# The ./ with the ls is there on purpose to make it safer
# from potential globbing issues
for old_fn in $(ls ./*.jpg)
Just stop it right now!  Stop doing that!
Just don't!
`for old_fn in *.jpg` is all you need, all you want.  Then make sure
"$old_fn" is properly quoted elsewhere.
That's okay, so long as there is at least one target file, otherwise it
fails.

I've added a test before now and dropped the ls in the for.

There was another minor change, formatting the number to be 3 digits
with printf isn't necessary in the use case.

$ cat photo-wrk.sh
#!/bin/bash

set -u

create_some_files() {
	declare -a old_filenames
	old_filenames=(
	'10062005.jpg'
	'10062005(121).jpg'
	'10062005(122).jpg'
	'10062005(123).jpg'
	)

	for old_fn in "${old_filenames[@]}"
	do
		touch "${old_fn}"
	done
}

#create_some_files # for testing
#exit

ls ./*.jpg &>/dev/null || {
	echo no jpg files to process
	exit
}

# create new_names dir if it doesn't exist
[[ -d ./new_names ]] || {
	mkdir new_names
}

for old_fn in *.jpg
do

	# if filename has only 12 characters (including .jpg)
	# then it doesn't have a counter value, so give it 0
	if [[ ${#old_fn} -eq 12 ]]
	then
		counterx=000
	else
		# if it has a counter, it is supposed to already have 3 digits
		counterx=${old_fn:9:3}
	fi

	# Get date in seconds from epoc
	# - using old file name format of DDMMYYYY
	ab=$(date -d "${old_fn:4:4}-${old_fn:2:2}-${old_fn:0:2}" +%s)

	# Add day counter for photos in seconds
	ab=$((ab + counterx))

	new_fn=$(date +%Y%m%d -d "@${ab}")"(${counterx}).jpg"
	mv "${old_fn}" ./new_names/"${new_fn}"
	touch -d "@${ab}" "./new_names/${new_fn}"
done

ls -l --full-time "./new_names/"

Cheers
A.