Bash correction (#922)

* fix bash path split example

* add two string equality and example

bash.md

@@ -154,8 +154,8 @@ echo ${STR:-5:5}  # "world"
 
 ```bash
 SRC="/path/to/foo.cpp"
-BASE=${STR##*/}   #=> "foo.cpp" (basepath)
-DIR=${SRC%$BASE}  #=> "/path/to" (dirpath)
+BASE=${SRC##*/}   #=> "foo.cpp" (basepath)
+DIR=${SRC%$BASE}  #=> "/path/to/" (dirpath)
 ```
 
 ### Substitution
@@ -333,6 +333,7 @@ Conditionals
 | `[ NUM -gt NUM ]`        | Greater than          |
 | `[ NUM -ge NUM ]`        | Greater than or equal |
 | ---                      | ---                   |
+| `[[ STRING == STRING ]]` | Equal                 |
 | `[[ STRING =~ STRING ]]` | Regexp                |
 | ---                      | ---                   |
 | `(( NUM < NUM ))`        | Numeric conditions    |
@@ -380,6 +381,11 @@ if [ X ] && [ Y ]; then
 fi
 ```
 
+```bash
+# Equal
+if [[ "$A" == "$B" ]]
+```
+
 ```bash
 # Regex
 if [[ "A" =~ "." ]]