6

I have been trying to:

cp file.csv file.$(date +%D).csv

But it fails because the filenames is: file.03/27/19.csv with the slash of separate directories.

And I have been trying again to:

cp file.csv file.$(printf "%q" $(date +%D)).csv

But it still fails.

  • You can not set a filename with slash characters: stackoverflow.com/questions/9847288/… – tres.14159 Mar 27 at 17:31
  • the problem is your use of the date format using the / character. You said it yourself, the shell is seeing them as directory markers. Try one of the many other options available from date. You might be able to get the / escaped so the filename uses the character code (like putting a space in a filename), but that is often problematic. – 0xSheepdog Mar 27 at 17:32
19

You can't have / (byte 0x2F on ASCII-based systems) in a file name, period.

You can use characters that look like / like (U+2215 division slash) or (U+2044 fraction slash though found in fewer of the charsets used in current locales), so you could do (provided that U+2215 character exists in the locale's charset, includes GBK, BIG5, UTF-8, GB18030):

cp file.csv "file.$(date +%D | sed 's|/|∕|g').csv"

Or with some shells (zsh, bash at least):

cp file.csv "file.$(date +%D | sed $'s|/|\u2215|g').csv"

(here using sed instead of tr as some tr implementations including GNU tr still don't support multi-byte characters).

But you may run into problems like the file name being rendered differently in locales using a different charset from the one that was in use at the time you created the file (and of course the confusion of users when they see what looks like a slash in a file name).

My advice would be to use the standard non-ambiguous (for most people outside the US, 03/12/18 would be interpreted as the 3rd of December 2018 for instance) YYYY-mm-dd format instead (which also helps wrt sorting):

cp file.csv "file.$(date +%Y-%m-%d).csv"

Which with many date implementations you can shorten to:

cp file.csv "file.$(date +%F).csv"
  • 2
    Other characters similar to slash can also be cumbersome to type in terminal. – gronostaj Mar 28 at 8:49
  • @gronostaj, I've added a method to specify the character based on its Unicode codepoint. – Stéphane Chazelas Mar 28 at 16:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.