I cannot figure out the correct use of find with -regex option:
For example, given this example:
Morcheeba/Big Calm/02 Shoulder Holster.flac
Morcheeba/Big Calm/02. Shoulder Holster.flac
I only want to match the string in the form path/to/file/## filename.ext, without the dot.
I've tried with:
find Morcheeba/ -regextype egrep -iregex ".*[0-9]{2}*[a-z]*flac$"
and some variation, but I always get all files either none.
What's wrong?
Thanks in advance.
Note that -regex/-iregex (GNU extensions also found on BSDs with different regex syntax), like the standard -path match on the full path, not just the file name.
If you want to find files whose name (as opposed to path) starts with 2 decimal digits, following by something that is not a decimal digit¹ and ending in .flac, you could do portably:
find . -name '[0-9][0-9][!0-9]*.[fF][lL][aA][cC]'
Note that it wouldn't match on 01.flac because the [!0-9] can't match there. Instead you could write it:
find . -name '[0-9][0-9][!0-9]*' -name '*.[fF][lL][aA][cC]'
Those use wildcard patterns, not regexps.
To use GNU find's -iregex, the equivalents would be:
find . -regextype egrep -iregex '.*/[0-9]{2}[^0-9/][^/]*\.flac'
find . -regextype egrep -iregex '.*/[0-9]{2}([^0-9/][^/]*)?\.flac'
That is, we anchor the two digits at the start, as we make sure the rest of the regexp doesn't span a /.
¹ Note that depending on locale and system, [0-9] may match on more characters (or even possible collating elements made of more than one character!) than just 0123456789. Use [0123456789] to be sure.
-E is the equivalent of GNU find's -regextype egrep or -regextype posix-extended. See man find for details. There's a currently open feature request for that -E to be added to GNU find as it's arguably far less cumbersome to use.
As suggested by @steeldriver, the regex .*[0-9]{2}[^.]*\.flac worked properly.
./path/to/foo123.flac or ./foo/1234/whatever.flac though.
.and*. In your example, the second*could be a space and the third*should be a.or\.. You could use[^\.]to match any character that is not a period. Put a*after it to match 0 or more non-period characters.