What's special about -eq compared to = and == ?

• A. -eq compares integers; strings may fail; = and == work with integers and strings.
• B. -eq compares strings; = works with strings only
• C. -eq is for assignment
• D. -eq cannot compare numbers

Answer: (A)

In shell tests, there are dedicated operators for numeric versus string comparisons. The -eq operator is the numeric equality test: it treats both operands as integers and compares their numeric values. If either operand isn’t a valid integer, the test fails with an error like “integer expression expected,” which is what “strings may fail” is pointing to.

In contrast, the = and the == operators are used for string comparisons. They compare the textual content of the operands rather than interpreting them as numbers. In Bash, = is the standard string equality operator in POSIX-style tests, while == inside the Bash-style [[ ... ]] test also handles string comparison and can support pattern matching with wildcards.

So the special thing about -eq is that it enforces numeric comparison, whereas = and == are for comparing text.