`stdlib_system`: essential path functionality #999

wassup05 · 2025-06-07T10:49:54Z

A few path related functions for ease of future functionality have been added.

joinpath: joins the given paths according to the platform's path-separator.
operator(/): as was suggested in the Fortran discourse here an operator is also provided for the same functionality
splitpath: splits the path following the last path-separator and returns the head and tail.
basename: just returns the tail of splitpath
dirname: just returns the head of splitpath

The pathsep parameter contains either / or \ depending on the platform and is a compile-time constant now, so is the parameter, ISWIN

Do let me know your thoughts.

sebastian-mutz · 2025-06-10T14:20:03Z

Thanks for the PR, @wassup05. Just a minor point (not related to functionality) about examples for now: It's always useful - esp. for those learning by examples - to have an idea of the expected output. Other stdlib examples add the expected print results as a comment below the respective commands. I would recommend to do the same here.

wassup05 · 2025-06-11T16:33:50Z

I will add that with the other reviews @sebastian-mutz, I don't want to trigger the ci/cd workflow just for a few comments. Also on a second thought maybe instead of the if (ISWIN) ... thing I could separate the two examples...

doc/specs/stdlib_system.md

example/system/example_path_1.f90

example/system/example_path_1_windows.f90

… declarations

jalvesz · 2025-06-15T18:36:52Z

The issue with Ninja detecting a "circular dependency" (there was non) was related to the stdlib_system.F90 file not being visible in a correct manner in the CMakeLists.txt file.

The group:

# Preprocessed files to contain preprocessor directives -> .F90
set(cppFiles

corresponds to .fypp files for which the suffix should be changed to .F90. Not for already .F90 files.

jalvesz

LGTM @wassup05! Thanks for this nice work!!

Copilot

Pull Request Overview

This PR introduces essential path manipulation functions and related operator overloads to simplify path handling across platforms. Key changes include:

Implementation of joinpath (and its operator(/)) for concatenating paths.
Addition of splitpath and its derivatives (basename, dirname) for decomposing paths.
Updates to tests, examples, documentation, and build files to support and illustrate the new functionality.

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
test/system/test_path.f90	Adds unit tests for new path functions and operator functionality.
test/system/CMakeLists.txt	Registers the new "path" test.
src/stdlib_system_path.f90	Implements joinpath, operator(/), splitpath, basename, and dirname.
src/stdlib_system.F90	Defines interfaces and exports for the new path functionality.
src/CMakeLists.txt	Includes the new path source file in the build.
example/system/*.f90	Provides usage examples for joinpath, splitpath, dirname, and basename.
doc/specs/stdlib_system.md	Updates the spec documentation to incorporate the new interfaces.
config/fypp_deployment.py	Passes the uppercase system name flag to the build commands.
CMakeLists.txt	Adds compile options to define the system name macro.

Comments suppressed due to low confidence (2)

example/system/example_path_dirname.f90:2

The program name 'example_path_splitpath' does not match the file's purpose (dirname functionality). Consider renaming it to 'example_path_dirname'.

program example_path_splitpath

example/system/example_path_basename.f90:2

The program name 'example_path_splitpath' in this file appears to be a copy-paste error; it should reflect basename functionality (e.g., 'example_path_basename').

program example_path_splitpath

perazz

Nice start @wassup05, thank you for this PR. It's a bit long so I tried to give some initial comments first hand. Let's first discuss and iterate around these comments, and then we can start planning about more path functionality, thank you.

perazz · 2025-06-19T09:07:16Z

CMakeLists.txt

@@ -31,6 +31,12 @@ if(CMAKE_Fortran_COMPILER_ID STREQUAL GNU AND CMAKE_Fortran_COMPILER_VERSION VER
  message(FATAL_ERROR "GCC Version 9 or newer required")
 endif()

+# Convert CMAKE_SYSTEM_NAME to uppercase


It is not currently possible to pass system-specific pre-processor flags to an fpm build of stdlib. So, I suggest CMake-determined macros should be removed.

perazz · 2025-06-19T09:08:03Z

config/fypp_deployment.py

@@ -115,6 +116,7 @@ def fpm_build(args,unknown):
    for idx, arg in enumerate(unknown):
        if arg.startswith("--flag"):
            flags= flags + unknown[idx+1]
+    flags = flags + "-D{}".format(platform.system().upper())


System-dependent pre-processor flags cannot be passed to the stdlib-fpm-* branches.

perazz · 2025-06-19T09:11:47Z

doc/specs/stdlib_system.md

@@ -532,3 +532,175 @@ The file is removed from the filesystem if the operation is successful. If the o
 ```fortran
 {!example/system/example_delete_file.f90!}
 ```
+
+## `joinpath` - Joins the provided paths according to the OS


Quoting #939 (review), I agree it would be a good idea to keep the naming convention as homogeneous as possible. In this case it would be join_path with snake case.

perazz · 2025-06-19T09:21:31Z

src/stdlib_system.F90

@@ -83,7 +83,22 @@ module stdlib_system
 public :: kill
 public :: elapsed
 public :: is_windows
-
+
+!! Public path related functions and interfaces


Because of the said limitations, I would discourage to define these parameters with pre-processor flags. I would suggest the same approach for OS_TYPE be also adopted here.

perazz · 2025-06-19T09:23:39Z

src/stdlib_system.F90

+    logical, parameter, public :: ISWIN = .true.
+#else
+    character(len=1), parameter, public :: pathsep = '/'
+    logical, parameter, public :: ISWIN = .false.


ISWIN looks like a duplicate definition for OS_TYPE()==OS_WINDOWS, so I suggest to remove it altogether and use what stdlib already offers at this stage. pathsep or rather path_sep would become a function: how about just sep such as in Matlab? Or, something familiar to other libraries would be fine imho.

perazz · 2025-06-19T09:24:31Z

src/stdlib_system.F90

+public :: joinpath
+public :: operator(/)
+public :: splitpath
+public :: basename
+public :: dirname


Could you please add short FORD comment blocks for theese APIs? As an example:

stdlib/src/stdlib_system.F90

Lines 102 to 116 in ca867f8

!! version: experimental

!!

!! Tests if a given path matches an existing directory.

!! ([Specification](../page/specs/stdlib_system.html#is_directory-test-if-a-path-is-a-directory))

!!

!!### Summary

!! Function to evaluate whether a specified path corresponds to an existing directory.

!!

!!### Description

!!

!! This function checks if a given file system path is a directory. It is cross-platform and utilizes

!! native system calls. It supports common operating systems such as Linux, macOS,

!! Windows, and various UNIX-like environments. On unsupported operating systems, the function will return `.false.`.

!!

public :: is_directory

If the documentation is added here, it should be placed following the interface declaration or within the function declaration if there is no additional interface, and not before the public statement as it is done within this module currently. I actually have issues with FORD locally to produce the documentation because of that but haven't mention it yet to avoid mixing issues within the same PR.

Yes, it is a good idea to address (these and perhaps more of) FORD issues in a separate PR. For the current PR, I think it's ok to stay consistent with the current syntax.

perazz · 2025-06-19T09:27:00Z

test/system/test_path.f90

+            paths = [character(20) :: 'C:','Users','Bob','Pictures','2025']
+            path = joinpath(paths)
+
+            call checkpath(error, 'joinpath', 'C:\Users\Bob\Pictures\2025', path)


One of the usual issues with MS Windows is paths with spaces. What will happen if we try to join "C:\Users\John Doe" (note the quotes) + Pictures + 2025?

perazz · 2025-06-19T09:27:37Z

src/stdlib_system.F90

+    end function join_op
+end interface operator(/)
+
+interface splitpath


I suggest to rename this to split_path for stdlib style guide.

perazz · 2025-06-19T09:28:17Z

src/stdlib_system.F90

+    end subroutine splitpath
+end interface splitpath
+
+interface basename


I suggest to rename this to base_name for consistency with the style guide.

perazz · 2025-06-19T09:28:32Z

src/stdlib_system.F90

+    end function basename
+end interface basename
+
+interface dirname


I suggest to rename this to dir_name for consistency with the style guide.

wassup05 added 6 commits June 7, 2025 16:01

added interfaces and necessary build stuff

657b312

implemented interfaces

f41dee4

example

572ad46

tests added

8a10f26

added specs

1bd58b7

an edge case handled

ea71960

jalvesz reviewed Jun 12, 2025

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doc/specs/stdlib_system.md Outdated Show resolved Hide resolved

example/system/example_path_1.f90 Outdated Show resolved Hide resolved

wassup05 commented Jun 12, 2025

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example/system/example_path_1_windows.f90 Outdated Show resolved Hide resolved

separated examples according to OS and functions

c561108

wassup05 force-pushed the path branch from 8581c77 to c561108 Compare June 13, 2025 16:15

wassup05 requested a review from jalvesz June 15, 2025 09:12

jalvesz added 2 commits June 15, 2025 19:59

further split examples and fix some autodoc links issues due to wrong…

272eb67

… declarations

misslocation of source file

5147094

jalvesz approved these changes Jun 15, 2025

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jalvesz requested review from perazz, jvdp1 and Copilot June 15, 2025 18:42

Copilot AI reviewed Jun 15, 2025

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jalvesz and others added 2 commits June 15, 2025 20:46

fix example program names

9e64094

fix example_path_join.f90

ca867f8

perazz requested changes Jun 19, 2025

View reviewed changes

	!! version: experimental
	!!
	!! Tests if a given path matches an existing directory.
	!! ([Specification](../page/specs/stdlib_system.html#is_directory-test-if-a-path-is-a-directory))
	!!
	!!### Summary
	!! Function to evaluate whether a specified path corresponds to an existing directory.
	!!
	!!### Description
	!!
	!! This function checks if a given file system path is a directory. It is cross-platform and utilizes
	!! native system calls. It supports common operating systems such as Linux, macOS,
	!! Windows, and various UNIX-like environments. On unsupported operating systems, the function will return `.false.`.
	!!
	public :: is_directory

stdlib_system: essential path functionality #999

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stdlib_system: essential path functionality #999

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wassup05 commented Jun 7, 2025

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`stdlib_system`: essential path functionality #999

`stdlib_system`: essential path functionality #999

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