How can I suppress error messages of a command?

Most Unix commands, including ls, will write regular output to standard output and error messages to standard error, so you can use Bash redirection to throw away the error messages while leaving the regular output in place:

ls *.zip 2> /dev/null

$ ls *.zip 2>/dev/null

will redirect any error messages on stderr to /dev/null (i.e. you won't see them)

Note the return value (given by $?) will still reflect that an error occurred.

To suppress error messages and also return the exit status zero, append || true. For example:

$ ls *.zip && echo hello
ls: cannot access *.zip: No such file or directory
$ ls *.zip 2>/dev/null && echo hello
$ ls *.zip 2>/dev/null || true && echo hello
hello

$ touch x.zip
$ ls *.zip 2>/dev/null || true && echo hello
x.zip
hello