Dear coreutils : I am a Research and Development Engineer in IT. I met a situation when I use “sort” command in Linux shell which could be a bug for the "sort" command. So I hope you read this email, thank you ! The whole command I used was : *sort test.txt* *And the result was :* 20171012|3|2059517|-|8|-|20-24|2|-|2.0|2.0 20171012|3|2059517|-|82|-|25-29|2|-|13.0|12.0 20171012|3|2059517|-|8|-|-2|-2|-|71.0|64.0 20171012|3|2059517|-|82|-|30-34|0|-|2.0|1.0 *The content in test.txt was:* 20171012|3|2059517|-|8|-|20-24|2|-|2.0|2.0 20171012|3|2059517|-|82|-|25-29|2|-|13.0|12.0 20171012|3|2059517|-|8|-|-2|-2|-|71.0|64.0 20171012|3|2059517|-|82|-|30-34|0|-|2.0|1.0 *Which means the “sort” command didn't work, because I think the correct result should be :* 20171012|3|2059517|-|8|-|20-24|2|-|2.0|2.0 20171012|3|2059517|-|8|-|20-24|2|-|2.0|2.0 20171012|3|2059517|-|82|-|25-29|2|-|13.0|12.0 20171012|3|2059517|-|82|-|25-29|2|-|13.0|12.0 *The version of "sort" command I use is : sort --version* "sort (GNU coreutils) 8.4 Copyright (C) 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later . This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by Mike Haertel and Paul Eggert." *I am not sure if it is a bug in "sort" command in Linux Shell or maybe it's only my problems in using it.* *So I am look forward to receive your reply as soon as possible. * *Thank you very much!* Sincerely yours, Frank