Batch read file name and change content creation date

If the naming convention is the same for all files in the same directory, then in Terminal, cd to that directory and use the following compound command:

for f in *.*; do touch -t $(sed -e 's:\.[a-z].*::' -e 's:\.::' -e 's:[- ]::g'<<<"$f") "$f"; done

Explanation of some of the compound command:

• for f in *.*; do ...; done - Loop through files.
• touch -t [[CC]YY]MMDDhhmm[.SS] - Change the access and modification times to the specified time instead of the current time of day.
• $(...) - Command substitution, replaces the command(s) with the result, literally.
• sed - Stream editor for filtering and transforming text.
  • −e script - Add the script to the commands to be executed.
  • 's:\.[a-z].*::' - This strips the file extension in e.g.: 2012-04-05 19.21.34.jpg
    • Returns: 2012-04-05 19.21.34
  • 's:\.::' - This removes the first . in e.g.: 2012-04-05 19.21.34
    • Returns: 2012-04-05 1921.34
  • 's:[- ]::g' - This removes - and the space in e.g.: 2012-04-05 1921.34
    • Returns: 201204051921.34

Which is the perfect format for the -t option in the touch command.

Please note that the original compound command is formed a bit loose. In other words, it can be written to expressly target .jpg files where the extension is lower case as in your example, e.g.: 2012-04-05 19.21.34.jpg

• Replacing the *.* in for f in *.*; do ...; done with: in *.jpg
• Replacing the [a-z].* in sed -e 's:\.[a-z].*::' with: jpg
  

for f in *.jpg; do touch -t $(sed -e 's:\.jpg::' -e 's:\.::' -e 's:[- ]::g'<<<"$f") "$f"; done

Since the -t option is being used with the touch command, any filename that doesn't produce the expected output, the worst case scenario with it written a bit loose is its not going to impact non-target files and will simply error out on those files with:

touch: out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]

So, written a bit loose or more targeted, the end results will be the same and, only files with the naming convention of e.g. 2012-04-05 19.21.34.jpg will be touched.

NOTE: Always make sure you have a current backup before wholesale processing files.