Bigbro's foray into the scary world of blogging
From the ILUG mailing list, Padraig Brady had the following useful tips (repeated here so that I can find them and maybe not forget them):
Following on from my previous mail about finding cruft on a debian system with: (cat /var/lib/dpkg/info*.list ; find / -type f ) | LANG=C sort | uniq -u I find set operations like that quite common on the command line: For unsorted files: LANG=C sort file1 file2 | uniq #Union LANG=C sort file1 file2 | uniq -d #Intersection LANG=C sort file1 file1 file2 | uniq -u #Difference LANG=C sort file1 file2 | uniq -u #Symmetric Difference For sorted files: LANG=C comm file1 file2 | sed 's/^\t*//' #Union LANG=C comm -12 file1 file2 #Intersection LANG=C comm -13 file1 file2 #Difference LANG=C comm -3 file1 file2 | sed 's/^\t*//' #Symmetric Difference Note the LANG=C for speed as we're not interested in the actual order of the items. Padraig.
