Renaming a bunch of files with date modified timestamp at the end of the filename?

Question

So, say, I have a directory with a bunch of files like g.txt, where g.txt was last modified on, say, June 20, 2012.

How would I batch-rename all of the files (like g.txt) with the last modified date of June 20, 2012 appended on the end?

Answer 1

Quick-and-dirty Bash one-liner to rename all (globbed) files in the current directory from filename.txt to filename.txt-20120620:

for f in *; do mv -- "$f" "$f-$(stat -c %Y "$f" | date +%Y%m%d)"; done

An enterprising Bash nerd will find some edge case to break it, I'm sure. :)

Obviously, this doesn't do desirable things like checking whether a file already has something that looks like a date at the end.

Answer 2

here's a version of goldschrafe's one-liner that:

• doesn't use stat
• works with earlier versions of GNU date
• correctly copes with any spaces in the filenames

• also copes with filenames beginning with a dash

  for f in *; do mv -- "$f" "$f-$(date +%Y%m%d -r "${f}")"; done

Answer 3

Obligatory zsh one-liner (not counting the one-time loading of optional components):

zmodload zsh/stat
autoload -U zmv
zmv -n '(*)' '$1-$(stat -F %Y%m%d +mtime -- $1)'

We use the stat builtin from the zsh/stat module, and the zmv function to rename files. And here's an extra which places the date before the extension, if any.

zmv -n '(*)' '$1:r-$(stat -F %Y%m%d +mtime -- $1)${${1:e}:+.$1:e}'

Answer 4

As I understood we don't know beforehand what is the modification date. So we need to get it from each file, format the output and rename each file in a way so that it includes the modification date in the filenames.

You can save this script as something like "modif_date.sh" and make it executable. We invoke it with the target directory as the argument:

modif_date.sh txt_collection

Where "txt_collection" is the name of the directory where we have all the files that we want to rename.

#!/bin/sh

# Override any locale setting to get known month names
export LC_ALL=c
# First we check for the argument
if [ -z "$1" ]; then
    echo "Usage: $0 directory"
    exit 1
fi

# Here we check if the argument is an absolute or relative path. It works both ways
case "${1}" in
  /*) work_dir=${1};;
  *) work_dir=${PWD}/${1};;
esac

# We need a for loop to treat file by file inside our target directory
for i in *; do
    # If the modification date is in the same year, "ls -l" shows us the timestamp.
    # So in this case we use our current year. 
    test_year=`ls -Ggl "${work_dir}/${i}" | awk '{ print $6 }'`
    case ${test_year} in *:*) 
        modif_year=`date '+%Y'`
        ;;
    *)
        modif_year=${test_year}
        ;;
    esac
    # The month output from "ls -l" is in short names. We convert it to numbers.
    name_month=`ls -Ggl "${work_dir}/${i}" | awk '{ print $4 }'`
    case ${name_month} in
            Jan) num_month=01 ;;
            Feb) num_month=02 ;;
        Mar) num_month=03 ;;
        Apr) num_month=04 ;;
        May) num_month=05 ;;
        Jun) num_month=06 ;;
        Jul) num_month=07 ;;
        Aug) num_month=08 ;;
        Sep) num_month=09 ;;
        Oct) num_month=10 ;;
        Nov) num_month=11 ;;
        Dec) num_month=12 ;;
        *) echo "ERROR!"; exit 1 ;;
    esac
    # Here is the date we will use for each file
    modif_date=`ls -Ggl "${work_dir}/${i}" | awk '{ print $5 }'`${num_month}${modif_year}
    # And finally, here we actually rename each file to include
    # the last modification date as part of the filename.
    mv "${work_dir}/${i}" "${work_dir}/${i}-${modif_date}"
done