And without needing to invoke awk, you can do this entirely in the shell using:

Code:

for f in *_*_*_*.*
do      echo mv "$f" "${f%%_*}_${f#*_[0-9][0-9][0-9][0-9][0-9][0-9]}"
done

Despite what you learned in the last thread you started, what you need here is filename pattern matching and parameter expansion; not regular expressions. Filename patterns and REs are similar in some ways and very different in others. With an extended regular expression, you can match a specific number of a certain RE by enclosing the RE in parentheses in and following with that with \{number\}. But that isn't available in standard filename pattern matching. The parameter expansion ${f%%_*} expands $f with the longest string starting with _ removed from the end of the string (in this case expanding to ABC) and the parameter expansion ${f#*_[0-9][0-9][0-9][0-9][0-9][0-9]} expands $f with the shortest string ending with _ followed by seven digits from the start of the string (in this case 6197_20130708_203556.95336).

Note that you need to be sure that this is going to do what you want before you actually do it. The echo in red above shows you what it will do without actually renaming any of the files. If you run the script as shown using bash and the output looks right, remove the echo and run it again to actually rename the files. If you run this twice (without the echo) it will get rid of all 10 digits between the 1st two underscores in your filenames (and you won't have any way to recreate the original names) unless you make a backup copy of your files before you rename them.