With POSIX compliant sorts and uniqs (GNU uniq is currently not compliant in that regard), there's a difference in that sort uses the locale's collating algorithm to compare strings (will typically use strcoll() to compare strings) while uniq checks for byte-value identity (will typically use strcmp())¹. That matters for at least two reasons.

2022年5月30日 · My output consists of 1110 words for which sort -u keeps 1020 lines and uniq -u 1110 lines, the correct amount. The issue is that I cannot visually spot any duplicates on the list which is generated by using > at the end of the command line, and that there IS an issue with the total cracked passwords (in the context of customizing john the ripper).

2015年6月18日 · uniq with -u skips any lines that have duplicates. Thus: $ printf "%s\n" 1 1 2 3 | uniq 1 2 3 $ printf "%s\n" 1 1 2 3 | uniq -u 2 3 Usually, uniq prints lines at most once (assuming sorted input). This option actually prints lines which are truly unique (having not appeared again).

2014年11月26日 · | sort | uniq -c As stated in the comments. Piping the output into sort organises the output into alphabetical/numerical order. This is a requirement because uniq only matches on repeated lines, ie . a b a If you use uniq on this text file, it will return the following: a b a

2020年5月15日 · $ uniq -ic a.txt 2 A 2 B 1 Ş 1 ş How can I solve the non-ascii character problem with uniq? here is my ...

2016年2月3日 · The unix command uniq -u returns truly unique elements (as opposed to the default behavior of uniq). For example: echo -e "a\na\nb\nc\nc\nd\ne\ne\ne\nf" | uniq -u b d f How can this command be emulated in a column-restricted manner (i.e., finding columns with unique elements from a table). One can assume that the input is already sorted.

2023年6月18日 · uniq needs to buffer at least the last output line to be able to detect adjacent lines, I don't see any reason why it could not buffer it and pass it along the pipeline. I've tried tweaking line buffering as suggested here but the results are still the same for me.

2020年9月15日 · uniq -c -f 2 only compares the last field by skipping the first two with -f 2. It prepends the number of duplicated lines with the -c flag, so we have to transfer the count number to the last field. That is what awk '{$(NF+1)=$1;$1=""}1' does.

2021年7月16日 · uniq only removes adjacent repeated lines, "squeezing" the adjacent repeated lines into single lines. With -u (or --unique with GNU uniq), it also removes lines that had adjacent repeated lines. In you example, none of the three lines saying foo were ever adjacent to any other line saying foo. This is why they are outputted.

2018年6月29日 · The uniq -c part will still be using a single process. As Stéphane Chazelas points out in comments, the GNU implementation of sort is already parallelised (it's using POSIX threads), so modifying the number of concurrent threads is only needed if you want it to use more or fewer threads than what you have cores.