moving images

software

posted on January 5th, 2026 by Lee Cattarin

problem statement

today I decided to finally clean up the assets/img directory for this site. Since 2022, when I started this project, I’ve just been adding images directly to that directory with no further segmentation - messy of me, I know! It’s gotten unwieldy and I’m starting to get worried about generic names leading to duplicates at some point, particularly for the non-gallery images where I have a tendency to use lots of mushroom images.

so it’s time to move them into year-based folders. Let’s talk about how I did that. bash away!

(want to skip right to the completed script?)

find

let’s start with the basics: a list of posts. find gets us everything under a specific directory - in this case, the _posts directory. We can filter out the directories a few different ways, but I piped the find output through a basic grep looking for .md in the filename.

for FILE in $(find _posts | grep .md)
do
    # TBD
done

grep

grep can also help us get image names with the regex "name:.+jpg|png". I add name: to the regex because there are very occasionally images that aren’t the featured image for the post, and those don’t fit the pattern of name: <img>. Since there’s so few of those, I ended up handling them manually.

to make grep work with regex, it needs the -E flag.

# gives us
#     name: <img>
# note the 4 spaces at the beginning of the line
IMAGE_LINE=$(cat $FILE | grep -E "name:.+jpg|png$")

cut

that output gets us the full line of text that includes the image filename. Let’s trim out what we actually want.

below, -d sets a delimiter, and -f chooses what field we want to return. Because there’s 4 spaces before name, our field index is actually pretty high - cut is creating 4 empty strings.

IMAGE=$(echo $IMAGE_LINE | cut -d ' ' -f 6 -)

or, for brevity:

IMAGE=$(cat $FILE | grep -E "name:.+jpg|png$" | cut -d ' ' -f 6 -)

with cut, we can also get the year of the post:

YEAR=$(echo $FILE | cut -d '/' -f 2 -)

sed

there’s two major things we need to do with the information we’ve gathered:

1. replace the image filename in-place in the post’s markdown file
2. move the image file from its original location into a new directory

we can do replacement with sed, where our pattern should be something like this: s/$IMAGE/$YEAR\/&\ (the & subs in the found string - in this case $IMAGE). We could also use comma separators if we don’t want to escape the slash, like s,$IMAGE,$YEAR/&, - I did this for ease of reading.

by default, sed prints to standard output, so we’ll tell it to edit in-place instead with -i. Here’s our full sed command:

sed "s,$IMAGE,$YEAR/&," -i $FILE

mving and shaking

(my mom thinks I’m funny.)

now we’ll handle moving the image file from its original location into a new directory. let’s create our image paths, source and destination:

IMG_DIR=assets/img
NEW_IMAGE=$IMG_DIR/$YEAR/$IMAGE
IMAGE=$IMG_DIR/$IMAGE

trying to mv the images will immediately cause problems, because the year directories don’t exist yet. A simple check gets us past that:

if [ ! -d $IMG_DIR/$YEAR ]
then
    mkdir $IMG_DIR/$YEAR
fi

finally, we can mv the image:

mv $IMAGE $NEW_IMAGE

result

here’s our final script:

for FILE in $(find _posts | grep .md)
do
    # parse image and year info
    IMAGE=$(cat $FILE | grep -E "name:.+jpg|png$" | cut -d ' ' -f 6 -)
    YEAR=$(echo $FILE | cut -d '/' -f 2 -)

    # replace in-place in file
    sed "s,$IMAGE,$YEAR/&," -i $FILE

    # path creation
    IMG_DIR=assets/img
    NEW_IMAGE=$IMG_DIR/$YEAR/$IMAGE
    IMAGE=$IMG_DIR/$IMAGE

    # create dir for year if it doesn't exist
    if [ ! -d $IMG_DIR/$YEAR ]
    then
        mkdir $IMG_DIR/$YEAR
    fi

    # move image
    mv $IMAGE $NEW_IMAGE
done

questions? errors? ping me!

---