On Mon, 2008-12-01 at 00:25 +0000, Pádraig Brady wrote: > anonymous wrote: > > URL: > > <http://savannah.gnu.org/bugs/?24974> > > > > Hello, > > > > Could you explicitly document that "-1", "-2" and "-3" options > > of "comm" can be combined. > > This isn't obvious, and may lead some people [me!] to use > > other tools instead. > > It's common for options to be combined unless otherwise stated, > but I take your point that it's perhaps a little confusing. > Perhaps this change would make it more obvious? > It's not removing info as the info removed is already > presented on the previous line. > > diff --git a/src/comm.c b/src/comm.c > - -1 suppress lines unique to FILE1\n\ > + -1 suppress output of column 1\n\
Actually, I think both information are useful... Maybe something like: "suppress lines unique to FILE1 (suppress output of column 1)" but that's 79 character long... not really nice. So maybe: "suppress lines unique to FILE1 (i.e don't output column 1)" > I might add some examples to the docs also, along the lines > of the following if I get a second. At least I should get > the docs for `comm` and `join` to reference each other. Yes, I love examples in manpages. > # set operations on sorted files Maybe just focus on what each command does very well. > comm file1 file2 | sed 's/^\t*//' #Union > comm -12 file1 file2 #Intersection > comm -13 file1 file2 #Difference > comm -3 file1 file2 | sed 's/^\t*//' #Symmetric Difference "Print lines present in both file1 and file2 (Intersection)." comm -12 file1 file2 "Print lines not in the other file, both way (Symmetric Difference)" comm -3 file1 file2 | sed 's/^\t*//' > join -a1 -a2 file1 file2 #Union > join file1 file2 #Intersection > join -v2 file1 file2 #Difference > join -v1 -v2 file1 file2 #Symmetric Difference > # set operations on unsorted files > > sort file1 file2 | uniq #Union > sort file1 file2 | uniq -d #Intersection > sort file1 file1 file2 | uniq -u #Difference > sort file1 file2 | uniq -u #Symmetric Difference Note: This only works if the input files don't contain duplicated lines. "Print lines in file2 not present in file1 (Difference / Substraction):" grep -Fv -f file1 file2 "Print all distinct lines in file1 or file2 (Union):" sort -u file1 file 2 > p.s. Those new --check-order --nocheck-order options confuse me. > When they were added I only took a quick look at the implementation > rather than the interface (which Bo Borgerson kindly sped up for us). > Perhaps something like this would be clearer: That feature is great. Actually, it's worth emphasizing that files should be sorted in the manpage: the sentence "Compare sorted files FILE1 and FILE2 line by line." is quite clear... for those who read it carefully. may be : "Compare two files FILE1 and FILE2 line by line. Each file must be already sorted." Thanks, Franklin _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
