Most of us are familiar with the Useless Use of Cat Award which is awarded for unnecessary use of the cat
command. For example, in nearly all cases, cat file | command arg
can be rewritten as <file command arg
.
In a similar vein, this post is about the useless use of the echo
command. In nearly all cases:
echo string | command arg
can be rewritten using a heredoc:
command arg << END
string
END
or, using a here-string:
command arg <<< string
Note: Here-strings are not portable (but most modern shells support them) so use the heredoc alternative shown above if you are writing a portable script!
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