Well,
if [ "$1" == "" ] || [ $# -gt 1 ]; then
echo "Parameter 1 is empty"
First, use =
instead of ==
. The former is standard, the latter a bashism (though I think it's from ksh, too). Second, the logic here isn't right: if $#
is greater than one, then parameter 1 probably isn't empty (it might be set to the empty string, though). Perhaps you meant "$#" -lt 1
, though that would also imply that "$1" = ""
. It should be enough to test [ "$1" = "" ]
, or [ "$#" -lt 1 ]
.
elif [! "${#timestamp}" -gt 10 ]; then
Here, the shell would try to run a command called [!
(literally). You need a space in between, so [ ! "${#timestamp}" -gt 10 ]
. But that's the same as [ "${#timestamp}" -le 10 ]
, which would also catch strings of exactly 10 characters, like 2018-08-14
.
So maybe you want [ "${#timestamp}" -ne 10 ]
. (!=
instead of -ne
would also work, even though it's a string comparison.)
if ...
exit 0
It's customary to return with a non-zero exit code in case of an error, so use exit 1
in the error branches.
You could also use case
or [[ .. ]]
to pattern match the argument against the expected format, e.g.:
case "$1" in
"")
echo date is empty
exit 1;;
[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9])
echo date is ok;;
*)
echo "date is _not_ ok"
exit 1;;
esac
That would also reject arguments like abcdefghij
, even though it's 10 characters long.