Shell – how to strip the last slash of the directory path

Yes, this is a bit inconsistent, even within the GNU tools.

One problem with your proposal is that non-empty directories cannot be removed. Apart from that, -T (in GNU land, anyway) approximates what you want (the first case):

$ ls dira/ dirb/
dira/:
a

dirb/:
b
$ mv -iT dira/ dirb/
mv: overwrite `dirb/'? y
mv: cannot move `dira/' to `dirb/': Directory not empty
$ rm dirb/b 
$ mv -iT dira/ dirb/
mv: overwrite `dirb/'? y
$ ls dira/ dirb/
ls: cannot access dira/: No such file or directory
dirb/:
a

awk solution

awk '{print substr($2,1,4) substr($1,1,2)}' file

gives you the directory names.

mkdir $(awk '{print substr($2,1,4) substr($1,1,2)}' file)

creates the directories (if they are not too many). For huge numbers (10,000+) you can use:

awk '{print substr($2,1,4) substr($1,1,2)}' file | xargs --delimiter=\\n mkdir

bash solution

awk is not necessary, the shell can do that itself:

while read first last rest; do mkdir -p "${last:0:4}${first:0:2}"; done <file