Add docs

Author: minhqdao

doc/specs/stdlib_io.md

@@ -123,6 +123,149 @@ Provides a text file called `filename` that contains the rank-2 `array`.
 {!example/io/example_savetxt.f90!}
 ```
 
+## `is_windows`
+
+### Status
+
+Experimental
+
+### Description
+
+Returns a logical value indicating whether the current operating system is Windows.
+
+### Syntax
+
+`is_windows = ` [[stdlib_io_filesystem(module):is_windows(function)]] `()`
+
+### Return value
+
+A logical value indicating whether the current operating system is Windows.
+
+## `path_separator`
+
+### Status
+
+Experimental
+
+### Description
+
+Returns the path separator for the current operating system.
+
+### Syntax
+
+`separator = ` [[stdlib_io_filesystem(module):path_separator(function)]] `()`
+
+### Return value
+
+A character value containing the path separator for the current operating system.
+
+## `exists`
+
+### Status
+
+Experimental
+
+### Description
+
+Determines if a file or directory exists at the given path by returning a logical value.
+
+### Syntax
+
+`exists = ` [[stdlib_io_filesystem(module):exists(function)]] `(path)`
+
+### Arguments
+
+`path`: Shall be a character expression containing the path to a file or directory to check for existence.
+
+### Return value
+
+A logical value indicating whether a file or directory exists at the given path.
+
+## `list_dir`
+
+### Status
+
+Experimental
+
+### Description
+
+Lists the contents of a directory.
+
+### Syntax
+
+`call ` [[stdlib_io_filesystem(module):list_dir(subroutine)]] `(dir, files[, iostat][, iomsg])`
+
+### Arguments
+
+`dir`: Shall be a character expression containing the path to the directory to list.
+
+`files`: Shall be an allocatable rank-1 array of type `string_type` that will contain the names of the files and directories in the directory.
+
+`iostat`: Shall be a scalar of type `integer` that receives the error status of `list_dir`. Optional argument.
+
+`iomsg`: Shall be a deferred length character variable that receives the error message of `list_dir`. Optional argument.
+
+## `mkdir`
+
+### Status
+
+Experimental
+
+### Description
+
+Creates a new directory.
+
+### Syntax
+
+`call ` [[stdlib_io_filesystem(module):mkdir(subroutine)]] `(dir[, iostat][, iomsg])`
+
+### Arguments
+
+`dir`: Shall be a character expression containing the path to the directory to create.
+
+`iostat`: Shall be a scalar of type `integer` that receives the error status of `mkdir`. Optional argument.
+
+`iomsg`: Shall be a deferred length character variable that receives the error message of `mkdir`. Optional argument.
+
+## `rmdir`
+
+### Status
+
+Experimental
+
+### Description
+
+Removes a directory.
+
+### Syntax
+
+`call ` [[stdlib_io_filesystem(module):rmdir(subroutine)]] `(dir)`
+
+### Arguments
+
+`dir`: Shall be a character expression containing the path to the directory to remove.
+
+## `run`
+
+### Status
+
+Experimental
+
+### Description
+
+Runs a command in the shell.
+
+### Syntax
+
+`call ` [[stdlib_io_filesystem(module):run(subroutine)]] `(command[, iostat][, iomsg])`
+
+### Arguments
+
+`command`: Shall be a character expression containing the command to run in the shell.
+
+`iostat`: Shall be a scalar of type `integer` that receives the error status of `run`. Optional argument.
+
+`iomsg`: Shall be a deferred length character variable that receives the error message of `run`. Optional argument.
 
 ## `load_npy`
 
@@ -164,7 +307,6 @@ Returns an allocated `array` with the content of `filename` in case of success.
 {!example/io/example_loadnpy.f90!}
 ```
 
-
 ## `save_npy`
 
 ### Status

src/stdlib_io_filesystem.F90

@@ -35,7 +35,7 @@ logical function is_windows()
 
     !> Version: experimental
     !>
-    !> Separator for paths.
+    !> Returns the path separator for the current operating system.
     !> [Specification](../page/specs/stdlib_io.html#path_separator)
     character function path_separator()
         if (is_windows()) then
@@ -49,14 +49,14 @@ character function path_separator()
     !>
     !> Whether a file or directory exists at the given path.
     !> [Specification](../page/specs/stdlib_io.html#exists)
-    logical function exists(filename)
-        !> Name of the file or directory.
-        character(len=*), intent(in) :: filename
+    logical function exists(path)
+        !> Path to a file or directory.
+        character(len=*), intent(in) :: path
 
-        inquire(file=filename, exist=exists)
+        inquire(file=path, exist=exists)
 
 #if defined(__INTEL_COMPILER)
-        if (.not. exists) inquire(directory=filename, exist=exists)
+        if (.not. exists) inquire(directory=path, exist=exists)
 #endif
     end