You have two problems:
-
Useless Use of Echo in Backticks
-
Always quote what you
echo
So the fixed code is
a=5
cronSen="*/$a * * * * bash /etc/init.d/ckDskCheck.sh"
echo "$cronSen"
It appears you may also have a Useless Use of Variable, but perhaps cronSen
is useful in a larger context.
In short, quote everything where you do not require the shell to perform token splitting and wildcard expansion.
Token splitting;
words="foo bar baz"
for word in $words; do
:
(This loops three times. Quoting $words
would only loop once over the literal token foo bar baz
.)
Wildcard expansion:
pattern='file*.txt'
ls $pattern
(Quoting $pattern
would attempt to list a single file whose name is literally file*.txt
.)
In more concrete terms, anything containing a filename should usually be quoted.
A variable containing a list of tokens to loop over or a wildcard to expand is less frequently seen, so we sometimes abbreviate to “quote everything unless you know precisely what you are doing”.