Motivation

I have met many novices who have no programming background and are mostly related to scientific computing. Fortran beginners often fail to master the reading of files well and will encounter EOF (End of File) errors.
If we can query the number of lines in the file in advance, we can slightly avoid EOF and guide the allocation of the allocatable array.

So, I see that there is already a function number_of_rows in stdlib_io, I think it can be overloaded:

interface count_lines
 module procedure :: number_of_rows
end interface count_lines
! - - -
counts = count_lines(unit)

Prior Art

Count lines:

• number_of_rows (stdlib_io)
• countlines1 (forlab_io)
• countlines2 (forlab_io)

Read the context of the file as a string (or array)

• toml-f.toml_parse
• fortran-csv-module.read_csv_file
• json-fortran.json_file_load

Additional Information

• counts = count_lines(filename [, iostat] )
• type(string_type) :: string(:)/string = read_file(unit/filename [, iostat] )
• call count_lines( unit/filename, lines [, columns, max_width, len_lines(:), iostat] )
• call count_lines( unit/file, lines [, max_width, iostat] )