What does this mean in a shell script?| sed 's/ /':'/' | sed 's/ /-/' > file.list
What does this sed command mean?
shell script;sed
Assuming the context issome-command | sed 's/ /':'/' | sed 's/ /-/' > file.listLet's break it apart piece by piece.  Suppose for example that some-command is echo 'test of the command'.Then sed 's/ /':'/' replaces the first space by :.test of the command test:of the commandAfter that, sed 's/ /-/' replaces the new first space by -test:of the command test:of-the commandThis transformation is applied on each line of the output of some-command.As mentioned by @Philippos in the comments, it is unclear why : is unquoted here.  It would be better assome-command | sed 's/ /:/' | sed 's/ /-/' > file.listBut sed is not restricted to a single replacement per instance.  So even better issome-command | sed 's/ /:/; s/ /-/' > file.list