Regex inside braces (curly brackets) -- gnu parallel / xargs / find
bash, curly-braces, parallel-processing, regex, shell
Solution
Yes, it appears you are missing something here. The linuxjournal article explains features of shell parameter expansion. Those braces (which are always preceded by `$`) are unrelated to `parallel` utility's default replacement strings, which coincidently use braces. The parallel documentation shows command line options allow arbitrary strings to be used instead of its brace-enclosed defaults.
For example the replacement string `{.}` in your example could be changed to `%foo`
ls * | parallel --extensionreplace %foo "mkdir ./%foo"
More information about `${…}` from the linuxjournal article can be found in the `man bash` page, in the Parameter Expansion section.
Since you asked in the comment on @AdamLiss answer, here is a way to (ab)use the curly braces and the `--colsep` parameter to perform your task:
ls * | parallel --colsep '\.' "mkdir ./{1}"
Note: this `--colsep` trick (like the `sed` proposed by @AdamLiss) will produce undesirable results if the filenames contain more than two periods (since the pathname is truncated at the first period.)
However, since the `--colsep` parameter is a regular expression, this should be resilient to periods elsewhere in the filename:
ls * | parallel --colsep '\.[^\.]*$' "mkdir ./{1.}"
Note: `--extensionreplace` isn't working due to a bug in the current (21120422) version of parallel. But since `parallel` is an a perl script, you can fix it by changing:
"extensionreplace|er" => \$::opt_U,
to
"extensionreplace|er=s" => \$::opt_U,
Problem
I'm having trouble with braces (curly brackets) using GNU parallel (http://www.gnu.org/software/parallel/) I have a list of four files: ``` file1.txt.super file2.txt.super file3.txt.super file4.txt.super ``` If I issue: `ls * | parallel "mkdir ./{.}"` I get returned four directories: ``` file1.txt file2.txt file3.txt file4.txt ``` My question is, how can I simply return four directories called: ``` file1 file2 file3 file4 ``` I have read http://www.linuxjournal.com/article/8919 but have been unable to implement these regex's with gnu parallel. I think I'm missing something here. Also, any examples with much more complicated regex would be very much appreciated.