Hi, I have the following problem. I need a script that will find in a .csv file dates of format
Mon Mar 05 18:34:38 1982
and change them to this format inside the file:
03051982
Can this be done with sed? Does it have the ability to find a something using regular expressions and then modify it rather than replacing it? Or must this be done in awk? Any answers would be awesome. Thanks a lot.

March 05 1982 was not a monday, but a friday.
But the line below will convert it correctly anyway:It should be possible with sed, but it would be a tedious task. Not recommended for sure (in this case, handling date conversion).

If the date fields are always at the start of the lines, you don't even need to search for them: just run "date" on the first 24 chars. If that's invalid, "date" will return non-zero exit code.

If the dates are in certain field number(s) of the csv file, I'd use awk. Have a look at the strftime() function of awk for conversion (this will be similar to the "date" example above).

If the dates can be anywhere in the lines of the CSV file, use grep to find the date strings, and convert them with "date". (see above)