Description
  A modern Fortran library for reading and writing CSV (comma-separated value) files.

Latest Release
GitHub release

Examples
Everything is handled by an object-oriented csv_file class. Here is an example for writing a file:

    program csv_write_test
    
    use csv_module
    use iso_fortran_env, only: wp => real64
    
    implicit none
    
    type(csv_file) :: f
    logical :: status_ok
    
    ! open the file
    call f%open('test.csv',n_cols=4,status_ok=status_ok)
    
    ! add header
    call f%add(['x','y','z','t'])
    call f%next_row()
    
    ! add some data:
    call f%add([1.0_wp,2.0_wp,3.0_wp],real_fmt='(F5.3)')
    call f%add(.true.)
    call f%next_row()
    call f%add([4.0_wp,5.0_wp,6.0_wp],real_fmt='(F5.3)')
    call f%add(.false.)
    call f%next_row()
    
    ! finished
    call f%close(status_ok)
    
    end program csv_write_test

Which produces the following file:

x,y,z,t
1.000,2.000,3.000,T
4.000,5.000,6.000,F
Real, integer, logical, or character data can be added as scalars, vectors, and matrices.

When reading a CSV file, the data is stored internally in the class as allocatable character strings, which can be retrieved as real, integer, logical or character vectors as necessary. For example, to get the x, y, z, and t vectors from the previously-generated file:

    program csv_read_test
    
    use csv_module
    use iso_fortran_env, only: wp => real64
    
    implicit none
    
    type(csv_file) :: f
    character(len=30),dimension(:),allocatable :: header
    real(wp),dimension(:),allocatable :: x,y,z
    logical,dimension(:),allocatable :: t
    logical :: status_ok
    integer,dimension(:),allocatable :: itypes
    
    ! read the file
    call f%read('test.csv',header_row=1,status_ok=status_ok)
    
    ! get the header and type info
    call f%get_header(header,status_ok)
    call f%variable_types(itypes,status_ok)
    
    ! get some data
    call f%get(1,x,status_ok)
    call f%get(2,y,status_ok)
    call f%get(3,z,status_ok)
    call f%get(4,t,status_ok)
    
    ! destroy the file
    call f%destroy()

    end program csv_read_test


Various options are user-selectable for specifying the format (e.g., changing the quote or delimiter characters). You can choose to enclose strings (or all fields) in quotes or not. The library works pretty well, and there are probably additional improvements that could be made. For one thing, it doesn't properly handle the case of a string that contains the delimiter character (I'll eventually fix this). If anybody has any other improvements, fork it and send me a pull request.

