Apologies. Wrong on every details. Sorry for wasting your time. On Sat, Aug 9, 2014 at 3:15 PM, bamber ward wrote: > I have tried to construct examples to test out \`(backslash backtick) but > have not succeeded in getting the responses I want. I assume that > backtick is the same as backquote. Backticks as in `command`. > for instance, > echo cat | sed "s/\`cat/bingo/" > gives cat > echo cat | sed "s/\`cat\'/bingo" # double quotes because of single quote > gives cat > but > echo cat | sed "s/cat\'/=/" gives > = > > > On Sat, Aug 9, 2014 at 2:13 PM, bamber ward wrote: > >> Unfortunately, errors in the documentation seem to persist. Somewhat >> disapointing but correcting >> bugs is, I find, a good way to really understand a language. >> >> Section 4.7 >> add >> s/.*// after last h >> to see why just run the program as given in the manual. >> >> Sections 4.9 and 4.10 >> in S!{ >> h >> b >> } >> add s/.*// after h >> omit final p >> without these changes you get, for >> a file containing, >> the cat sat >> on the mat # no new line here >> baa >> 23 >> 23 >> >> instead of 23 >> >> 4.15 >> I see you have added the -n option to this edition to try to correct >> this script. >> However, the comment in the script should state print the second(not >> first) duplicated line >> The program still does not give the correct output >> cat uniq_d3.txt >> dog >> dog >> cat >> cat >> pony >> gives output: >> dog >> cat >> cat >> pony >> >> instead of : >> dog >> cat >> >> The script prints out the last line regardless and if the last two lines >> are different it prints both. >> Replacing the last $b by >> $ s/.*/ / seems to fix it >> Possibilities >> Last two lines different.Can't be duplicates so delete >> Last two lines duplicates. >> Last line added in the code block. >> Last but one line deleted >> Then Last line printed so ok to delete pattern space at end. >> 4.17 >> Need to remove the first p in the last script to avoid duplicated output >> >> I hope you find this helpful >> Best Wishes >> >> David >> > >