-nt
is
undefined.#!/bin/sh
if [ Foo.java -nt Foo.class ]
then
javac Foo.java
fi
The easiest fix is to switch to a shell that does support
-nt
, like bash:
#!/bin/bash
if [ Foo.java -nt Foo.class ]
then
javac Foo.java
fi
Otherwise, find
can be used:
#!/bin/sh
if [ -n "$(find Foo.java -newer Foo.class)" ]
then
javac Foo.java
fi
test -nt
is an extension in ksh, bash and dash, but it
is not
specified by POSIX.
If you only intend to target shells that supports this feature, you can change the shebang to a shell that guarantees support, or ignore this warning.
You can use # shellcheck disable=SC3000-SC4000
to ignore
all such compatibility warnings.
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.