[[, [: add/update pages

pages/common/[.md

@@ -2,24 +2,24 @@
 
 > Check file types and compare values.
 > Returns 0 if the condition evaluates to true, 1 if it evaluates to false.
-> More information: <https://www.gnu.org/software/coreutils/test>.
+> More information: <https://www.gnu.org/software/bash/manual/bash.html#index-test>.
 
-- Test if a given variable is equal to a given string:
+- Test if a given variable is equal/not equal to the specified string:
 
-`[ "{{$VARIABLE}}" == "{{/bin/zsh}}" ]`
+`[ "${{variable}}" {{==|!=}} "{{string}}" ]`
 
-- Test if a given variable is empty:
+- Test if a given variable is [eq]ual/[n]ot [e]qual/[g]reater [t]han/[l]ess [t]han/[g]reater than or [e]qual/[l]ess than or [e]qual to the specified number:
 
-`[ -z "{{$GIT_BRANCH}}" ]`
+`[ "${{variable}}" -{{eq|ne|gt|lt|ge|le}} {{integer}} ]`
 
-- Test if a file exists:
+- Test if the specified [f]ile exists:
 
-`[ -f "{{path/to/file}}" ]`
+`[ -f {{path/to/file}} ]`
 
-- Test if a directory does not exist:
+- Test if the specified [d]irectory exists:
 
-`[ ! -d "{{path/to/directory}}" ]`
+`[ -d {{path/to/directory}} ]`
 
-- If-else statement:
+- Test if the specified file or directory [e]xists:
 
-`[ {{condition}} ] && {{echo "true"}} || {{echo "false"}}`
+`[ -e {{path/to/file_or_directory}} ]`

pages/common/[[.md

@@ -0,0 +1,29 @@
+# [[
+
+> Check file types and compare values.
+> Returns 0 if the condition evaluates to true, 1 if it evaluates to false.
+> More information: <https://www.gnu.org/software/bash/manual/bash.html#index-_005b_005b>.
+
+- Test if a given variable is equal/not equal to the specified string:
+
+`[[ ${{variable}} {{==|!=}} "{{string}}" ]]`
+
+- Test if a given string conforms the specified glob/regex:
+
+`[[ ${{variable}} {{==|=~}} {{pattern}} ]]`
+
+- Test if a given variable is [eq]ual/[n]ot [e]qual/[g]reater [t]han/[l]ess [t]han/[g]reater than or [e]qual/[l]ess than or [e]qual to the specified number:
+
+`[[ ${{variable}} -{{eq|ne|gt|lt|ge|le}} {{integer}} ]]`
+
+- Test if the specified [f]ile exists:
+
+`[[ -f {{path/to/file}} ]]`
+
+- Test if the specified [d]irectory exists:
+
+`[[ -d {{path/to/directory}} ]]`
+
+- Test if the specified file or directory [e]xists:
+
+`[[ -e {{path/to/file_or_directory}} ]]`