fortran-file

Fortran Functions for File Manipulation

• Wrapper functions of system operation commands

• Manipulate file or directory with the commands:
  touch, cp, mv, rm, mkdir, rmdir, cldir, print and find

• Can copy URI file to local via curl

• Change file encoding with cp if encoding differs

file_ty

type file_ty

  character(:), allocatable :: path     ! Full/relative path to a file
  character(:), allocatable :: dir      ! Directory name with tailing /
  character(:), allocatable :: name     ! File name with extention
  character(:), allocatable :: basename ! File name without extention
  character(:), allocatable :: ext      ! Extension of a file
  character(:), allocatable :: content  ! File content
  character(:), allocatable :: scheme   ! URI scheme {https, http, file}
  character(:), allocatable :: encoding ! File encoding
  character(1) :: type  = ''
  integer(8)   :: size  = 0
  logical      :: exist = .false.
  logical      :: local = .true.

contains

  procedure :: init  => init_file
  procedure :: print => print_file
  procedure :: touch
  procedure :: rm
  procedure :: cp
  procedure :: mv
  procedure :: mkdir
  procedure :: rmdir
  procedure :: cldir

end type

Initialization

Initialization process stores file_ty object with meta data of a file such as:
directory name, file name, base name, extension name, file size, and content information.

The derived type member (logical) exist is used for the status of actual file existence.

1. Single File Initialization

type(file_ty) :: file1, file2

call file1%init ( path = './dir_a/file_a1.txt' )

! With content option
call file2%init ( path = './dir_a/file_a2.txt', content = 'Weather Data' )

2. Multiple Files Initialization via File Search

type(file_ty), allocatable :: files(:)

files = find ( dir = './dir_a' )

• find is a wrapper function of the system operation command "find".
• Available options are: pattern, ignore, maxdepth, fullpath, type, and image.
• Use notation "|" for "OR" operator in pattern/ignore option (e.g., pattern = '*.txt | *.csv').
• Use image option for this_image() in coarray multi-threaded environment to avoid filelist file crash.

Print File

call file1%print

The above command prints file existence, file size and file path in the following way:

File/Directory exists: T, Size: 0B, Path: ./dir_test/dir_a/file_a1.txt

Make Empty File

An empty file on file_a4%path is made by the following command:

call touch ( file_a4 )

or

call file_a4%touch

file_a4%exist(default: .false.) becomes .true. after making the file.

File/Directory exists: T, Size: 0B, Path: ./dir_test/dir_a/file_a1.txt 

Remove File

A file on file_a4%path is removed by the following command:

call rm ( file_a4 )

or

call file_a4%rm

file_a4%exist becomes .false. after the removal of the file.

Copy File

A file on file_a1%path is copied to the place of file_c1%path by the following command:

call cp ( file_a1, file_c1 ) 

or

call file_a1%cp ( file_c1 ) 

Move File

A file on file_a2%path is moved to the place of file_c2%path by the following command:

call mv ( file_a2, file_c2 ) 

or

call file_a2%mv ( file_c2 ) 

file_a2%exist becomes .false. after the file move.

Make Directory

A directory dir_f is created recursively (mkdir -p) by the following command:

type(file_ty) :: dir_f
call dir_f%init ( path = './dir_f/' ) ! The tailing "/" is required to recognize directory

call mkdir ( dir_f )

or

call dir_f%mkdir

Remove Directory

A directory dir_f is removed if it is empty by the following command:

call rmdir ( dir_f )

or

call dir_f%rmdir

Clear Directory

A directory dir_f becomes empty by the following command:

call cldir ( dir_f )

or

call dir_f%cldir

Only files within the directory are recursively removed.

Obtain names

Use the following functions:

• dirname for directory name
• filename for file name with extension
• basename for file name without extension
• extname for extension name

dirname  ( './dir_test/dir_a/file_a1.txt' ) ! ./dir_test/dir_a/
filename ( './dir_test/dir_a/file_a1.txt' ) ! file_a1.txt 
basename ( './dir_test/dir_a/file_a1.txt' ) ! file_a1
extname  ( './dir_test/dir_a/file_a1.txt' ) ! .txt

Test Directory and Files

dir_test
├── dir_a
│   ├── file_a1.txt
│   ├── file_a2.csv
│   └── file_a3.html
└── dir_b (empty; not on GitHub)