The redirection takes place before your command. So basically what you told the system to do was:
1. Create the file dup_num. If the file exists overwrite it. 2. Redirect stdout of "uniq dup_num" into dup_num. Since you'd already overwritten the data in dup_num, there was nothing for uniq to process. On Tue, 28 Sep 2004 11:09:12 -0400, William Stanard <[EMAIL PROTECTED]> wrote: > In doing a demo before a class (Linux Red-hat 2.4.18-14), I used the uniq > command on a file (dup_nums) that consisted of twelve lines, each line > containing a number, from one to 9. I repeated the numbers, 6, 8, and 9. > The std output showed the expected list of numbers, all duplicates > removed. At a student's suggestion, I ran uniq again, but this time > directed the output to the file itself.... > > uniq dup_num > dup_num > > ...and, lo and behold, the file dup_num was empty. I checked uniq --help, > info uniq, and man uniq, all to no avail. Shouldn't uniq have removed the > duplicate numbers and written one through 9 to the file? > > Bill stanard > > - > To unsubscribe from this list: send the line "unsubscribe linux-newbie" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.linux-learn.org/faqs > -- http://xstonedogx.heroesmarket.net - To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs
