The Linux BASH provides many operators to check against test keyword
We are going to explain the Conditional comparison Operators for the Keyword parameter totest or [
For a detailed explanation of the Keyword test or [ Please refer to our Control Structure: Bash If then Else.
| File Comparison Operators |
Condition Explanation |
| -d “$file” | Returns true if the file exists and is a directory |
| -e “$file” | Returns true if the file exists. |
| -f “$file” | Returns true if the file exists and is a regular file |
| -h “$file” | Returns true if the file exists and is a symbolic link |
| String Comparators | Condition Explanation |
| “$str” = “$str2” | True if string $str is equal to string $str2. Not best for integers. |
| “$str” != “$str2” | True if the strings are not equal |
| -z “$str” | True if length of string is zero |
| -n “$str” | True if length of string is non-zero |
| Integer Comparators | Condition Explanation |
| “$int1” -eq “$int2” | True if the integers are equal |
| “$int1” -ne “$int2” | True if the integers are not equals |
| “$int1” -gt “$int2” | True if $int1 is greater than $int2 |
| “$int1” -ge “$int2” | True if $int1 is greater than or equal to $int2 |
| “$int1” -lt “$int2” | True if $int1 is less than $int2 |
| “$int1” -le “$int2” | True if $int1 is less than or equal to $int2 |