View source for Sed

The '''s'''tream '''ed'''itor. Sometimes the '''s'''hitty '''ed'''itor. <tt>sed</tt> works on lines at a time (mostly). Note that GNU and POSIX <tt>sed</tt> differ in some significant ways.

Use <tt>-i</tt> to run <tt>sed</tt> on a file inline. Never use e.g. <tt>cat file | sed > file</tt>; the shell redirection is going to open <tt>file</tt> for writing with truncation, which is probably not what you want. Supply expressions on the command line with <tt>-e</tt>, and/or files of expressions with <tt>-f</tt>.

==Recipes==
===Join pairs of lines===
<tt>sed 'N;s/\n/,/'</tt>