Strings are considered to be equal if each character in one is matched
exactly in the other, and they have the same length.
For example the following strings are not equal:
String is not equal to String.
While the strings contain the same letters, the second string contains
an extra space, and they are therefore not equal.
All of the string tests supported by test are listed in
table 2.5.
Table 2.5: String tests supported by test.