From 9ba11cff128876c9346498b1979b26e854b2d66a Mon Sep 17 00:00:00 2001 From: curben Date: Thu, 8 Nov 2018 17:28:43 +1030 Subject: [PATCH] docs: add 'Use Unix line endings in Unix tools' post --- source/_posts/unix-tools-line-endings.md | 36 ++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 source/_posts/unix-tools-line-endings.md diff --git a/source/_posts/unix-tools-line-endings.md b/source/_posts/unix-tools-line-endings.md new file mode 100644 index 0000000..e7255f3 --- /dev/null +++ b/source/_posts/unix-tools-line-endings.md @@ -0,0 +1,36 @@ +--- +title: Use Unix line endings in Unix tools +date: 2018-11-08 00:00:00 +tags: +--- + +Before you use any Unix tools to process some file, make sure the file only use Unix [line endings](https://en.wikipedia.org/wiki/Newline#Representation). + + + +Note that many text files you downloaded most probably use Windows line endings. + +To [recap](https://en.wikipedia.org/wiki/Newline#Representation), + +Type | Line ending | Escape sequence +---|--- | --- +Windows | CR LF | \r\n +Unix (including Linux distro, *BSD and macOS) | LF | \n +Classic Mac OS (i.e. Mac OS 9 or older) | CR | \r + +Unix tools, regardless from Busy/ToyBox, GNU or BSD, only support Unix line endings. + +So, before you use any of them, make sure you convert the file to Unix line endings, especially before `grep -f`. + +Use `dos2unix` to convert from Windows to Unix line endings, e.g. + +``` +# STDIN to STDOUT +cat input | dos2unix +# STDIN to FILE +cat input | dos2unix > output +# Convert and replace current file +dos2unix filename +``` + +If your distro includes BusyBox (e.g. Ubuntu), use `busybox dos2unix`. \ No newline at end of file