How to convert YYYYMMDDHHMMSS to a date readable by `date`

Question

I have a set of date/time strings in the YYYYMMDDHHMMSS format that I want to convert to something readable by the date utility. Usually, I can do something li

Answer 1

If the format is totally fixed, you could just do it within bash, chopping up the string:

d=20100101123456
pretty_date="${d:0:4}-${d:4:2}-${d:6:2} ${d:8:2}:${d:10:2}:${d:12:2}"
# 2010-01-01 12:34:56
...

I wouldn't bother trying to use regex - like you said, the pattern gets ugly fast. A lot of repetition of ([0-9]{4}), even with extended or perl regex. Or you could be flexible and just match .; no verification.