[Swan-dev] understanding output of the tests
D. Hugh Redelmeier
hugh at mimosa.com
Wed Apr 2 19:30:54 EEST 2014
| From: Paul Wouters <paul at nohats.ca>
| Why are the quotes needed when using : ?
: is really a command that does nothing, rather than a comment.
So redirection and variable expansion are done on the operands.
: >file
would actually create an empty file "file".
: '>file'
would act like
# >file
(# was introduced with the Bourne Shell. The original UNIX shell
(before the 7th Edition) didn't have it. ":" served two purposes in
the old shell: comments and labels (for control flow). The Bourne
Shell was a great advance in so many ways.)
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