3

I have a large number of files in a folder each with the date as the filename.
For example

20130101
20130102
20130103
.
.
.
20130131

similarly for other months 20130201 to 20130230, the pattern is [Year][Month][Day]. I need to make a tar file of the first fifteen files from JAN to APRIL (i.e 2013[01-04][01-15]), since double digit number range is not allowed in grep. How should I search this pattern?

5

With zsh:

tar zcf ~/file.tar.gz 20130<1-4><1-15>

If you have to use bash:

shopt -s extglob
tar zcf ~/file.tar.gz 20130[1-4]@(0?|1[0-5])
2

The grep bit is.

grep -zE "^20130[1-4](0[1-9]|1[0-5])$"
  • std grep will work as well. Since this particular pattern happens to want months 01-04, the first 0 can be included with the year. So, grep '20130[1-4][01..15]' will match the specified range. – bsd Dec 13 '13 at 11:44
  • 2
    @bdowning, no, [01..15], same as [015.] matches any of those 4 characters 0, 1, ., or 5. – Stéphane Chazelas Dec 13 '13 at 11:47
2

Use find to find the filenames:

find . -maxdepth 1 -name "20130[1-4]0?" -o -name "20130[1-4]1[0-5]" 

check if that is the correct set, and use the output as input for cpio:

find . -maxdepth 1 -name "20130[1-4]0?" -o -name "20130[1-4]1[0-5]" | cpio --create --format=ustar -O file.tar

@richard pointed out this could traverse in sub-directories (if a sub-directory matches the pattern) (and that shell expanded the pattern, corrected).

Expanding on the commandline runs the risk of the commandline becoming too long, which might happen if you had a file every few seconds for every day (20130101-00005, 20130101-00007. Piping the filename into cpio does not have problem.

  • 1
    Note it is not find that is doing the work here, but the shell. Warning will recurse directories, use echo instead of find to not do this. – ctrl-alt-delor Dec 13 '13 at 11:15
  • would'nt the space after question mark give an error? – Aditya Cherla Dec 13 '13 at 11:16
  • @Aditya why? it needs the space. – ctrl-alt-delor Dec 13 '13 at 11:19
  • @richard Sorry! my mistake just looked at an example of it – Aditya Cherla Dec 13 '13 at 11:22
  • Maybe call these first in your script shopt -s nullglob; shopt -u failglob, to stop it failing when a file is not found. – ctrl-alt-delor Dec 13 '13 at 11:28
0

You can tar czvf file.tar.gz $(ls | grep "201301\|201302\|201303\|201304" | grep -v "16\|17\|18\|19\|20\|21\|22\|23\|24\|25\|26\|27\|28\|29\|30\|31") from the base directory.

  • 3
    Beware though this should work it is fragile: e.g. if the year was 2016 it would not work. – ctrl-alt-delor Dec 13 '13 at 11:17

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