Path

Definition

A modern, portable Fortran module for path manipulation and basic directory operations. This module provides a clean interface for working with file system paths in a platform-independent way. It correctly handles both Unix ('/') and Windows ('\') path separators through conditional compilation and offers deferred-length character results for maximum flexibility.

The module builds upon the fpx_string module for string type support and provides overloads of key procedures to accept either intrinsic character(*) or type(string) arguments.

Features

• Detection of absolute and rooted paths on Windows and Unix-like systems
• Safe path joining that avoids duplicate separators
• Extraction of directory part, filename (with or without extension)
• Path splitting into head/tail components
• Retrieval of the current working directory (cwd)
• Changing the current working directory (chdir)

Note

All path-returning functions return allocatable deferred-length characters.

The public generic join interface works with any combination of character and string.

Examples

character(:), allocatable :: p1, p2, full
 
p1 = '/home/user/docs'
p2 = 'report.pdf'
full = join(p1, p2)                ! => '/home/user/docs/report.pdf'
 
print *, is_absolute(full)         ! .true.  (on Unix)
print *, filename(full)            ! 'report'
print *, filename(full,.true.)     ! 'report.pdf'
print *, dirpath(full)             ! '/home/user/docs'
...

On Windows:

character(:), allocatable :: p
p = join('C:\Users', 'Alice', 'Documents')
! p == 'C:\Users\Alice\Documents'
print *, is_absolute(p)   ! .true.
...

Data Types
interface	join
	Generic interface for joining two path components Supports all combinations of character and string arguments. More...

Methods

chdir()

subroutine chdir	(	character(*), intent(in)	path,
		integer, intent(out), optional	err )

Changes the current working directory.

Parameters

[in]	path	Directory to change to
[out]	err	Optional integer error code (0 = success, non-zero = failure) integer :: ierr call chdir('/tmp', ierr) if (ierr /= 0) stop 'Failed to change directory'

Remarks

Definition at line 422 of file path.f90.

cwd()

character(:) function, allocatable cwd

Returns the current working directory as a deferred-length character string. Returns empty string on failure.

Returns

res Current working directory

character(:), allocatable :: here
here = cwd()
print *, 'We are in: ', here

Remarks

Definition at line 392 of file path.f90.

dirname()

pure character(:) function, allocatable dirname

(

character(*), intent(in)

filepath

)

Returns the base name (filename) part of a path.

Parameters

[in]

filepath

Path to analyse

Returns

res Base name component

print *, dirname('/home/user/file.txt')  ! 'file.txt'

Remarks

Definition at line 313 of file path.f90.

dirpath()

pure character(:) function, allocatable dirpath

(

character(*), intent(in)

filepath

)

Returns the directory part of a path (everything before the last separator).

Parameters

[in]

filepath

Path to analyse

Returns

res Directory component

print *, dirpath('/home/user/file.txt')  ! '/home/user'

Remarks

Definition at line 294 of file path.f90.

filename()

pure character(:) function, allocatable filename	(	character(*), intent(in)	filepath,
		logical, intent(in), optional	keepext )

Extracts the filename part of a path. By default the extension is stripped. If keepext=.true. the full filename including extension is returned.

Parameters

[in]	filepath	Full or relative path
[in]	keepext	Optional; keep extension when .true.

Returns

res Filename (without path)

{.90} 
           print *, filename('dir/file.txt')        ! 'file'
           print *, filename('dir/file.txt',.true.) ! 'file.txt'
           print *, filename('archive.tar.gz')      ! 'archive.tar'

Remarks

Definition at line 179 of file path.f90.

is_absolute()

pure logical function is_absolute

(

character(*), intent(in)

filepath

)

Returns .true. if the path is absolute. On Unix a path is absolute when it starts with '/'. On Windows a path is absolute when it starts with a drive letter followed by ':\C:\', 'd:/temp').

Parameters

[in]

filepath

Path to test

Returns

res .true. if filepath is absolute

print *, is_absolute('/home/user')   ! .true.  (Unix)
print *, is_absolute('C:\\Temp')     ! .true.  (Windows)
print *, is_absolute('docs/..')      ! .false.
...

Remarks

Definition at line 127 of file path.f90.

is_rooted()

pure logical function is_rooted

(

character(*), intent(in)

filepath

)

Returns .true. if the path is rooted (starts with a separator) or is absolute. A rooted path begins with the platform separator ('\' on Windows, '/' elsewhere) even if it is not a full absolute path (e.g. '/temp' on Linux).

Parameters

[in]

filepath

Path to test

Returns

res .true. if filepath is rooted

Remarks

Definition at line 150 of file path.f90.

split_path()

pure subroutine split_path	(	character(*), intent(in)	filepath,
		character(:), intent(out), allocatable	head,
		character(:), intent(out), allocatable	tail )

Splits a path into head (directory) and tail (basename) components.

Parameters

[in]	filepath	Input path
[out]	head	Directory part (includes trailing separator when appropriate)
[out]	tail	Base name part

Remarks

Definition at line 329 of file path.f90.