mjhjmtu

I'm in a macOS environment.

I'd like to change the time stamp on multiple files that has names that starts with this format:

XXXXX_DD_MM_YYYY_HH-MM-SS_

This is an example of a filename:

CALLU_16-10-2018_10-58-26_p123456789012.mp3

Creation and modification date should be change to 16/10/2018 at 10:58:26.

I had the following script for filenames of the form Call@1234567890(1234567890)_20160624205913. It extracts date and time from the end of the file name, as a parameter for touch -t STAMP:

for f in *; do
 t="$(awk '/_.*/ match($0, /_.*/)
 print substr($0, RSTART + 1, RLENGTH - 7)
 '<<<"$f" )"
 touch -t "$t" "$f" 2>/dev/null
done

In your filename, the date is in little-endian format, so your awk script will need to swap the components, as well as removing all the separators:

awk -F '[-_]' 'print $4$3$2$5$6"."$7'

(If your input filenames contain additional - characters before the date, this will need rewriting.)

Test this with your example file:

$ echo 'CALLU_16-10-2018_10-58-26_p123456789012.mp3' | awk -F '[-_]' 'print $4$3$2$5$6"."$7'
201810161058.26

So your updated script could look something like:

for f in *.mp3; do
 t=$(echo "$f" | awk -F '[-_]' 'print $4$3$2$5$6"."$7')
 touch -t "$t" "$f"
done

Your old awk script was searching for the first _ in the filename, and then using everything from the next character (RSTART+1) to 6 characters before the end (RLENGTH-7: +1-7 = -6).

On your input filename, that would produce 20160624. touch expects the timestamp to be in the form:

[[CC]YY]MMDDhhmm[.SS]

...which would mean, with only 8 digits, the "20" is interpreted as the month, ie. an invalid date. But you wouldn't see touch reporting an error because of the 2>/dev/null.