Example file utility in Ada from PB

fileinfo.adb

with Ada.Text_IO; with ADA.IO_EXCEPTIONS;
with Ada.Command_Line;
with Ada.Directories;
with Ada.Strings.Bounded;
 
procedure FileInfo is
        -- rename used packages
        package IO renames Ada.Text_IO;
        package FS renames Ada.Directories;
        package Cmd renames Ada.Command_Line;
        -- alias the File_Size type
        subtype Size_Type is FS.File_Size;
       
        -- create bounded string
        Max_Length : constant Positive := 512;
        package FileName_String is new Ada.Strings.Bounded.Generic_Bounded_Length(Max_Length);
        use FileName_String;
       
        -- name of the info file
        FileName : Bounded_String;
        -- size of the file
        FileSize : Size_Type;
begin
        -- abort program if less than 1 argument
        if 1 > Cmd.Argument_Count then
                IO.Put_Line(Cmd.Command_Name & " requires at least 1 argument.");
                Cmd.Set_Exit_Status(Cmd.Failure);
                return;
        end if;
        -- get the first argument as input file
        FileName := To_Bounded_String(Cmd.Argument(1));
        -- check file existance
        if FS.Exists(To_String(FileName)) then
                IO.Put_Line("File '" & To_String(FileName) & "' exists.");
                -- check file type
                case FS.Kind(To_String(FileName)) is
                        when FS.Directory =>
                                IO.Put_Line(To_String(FileName) & " is a directory.");
                        when FS.Ordinary_File =>
                                IO.Put_Line(To_String(FileName) & " is an ordinary file.");
                        when FS.Special_File =>
                                IO.Put_Line(To_String(FileName) & " is a special file.");
                end case;
                -- get file size
                FileSize := FS.Size(To_String(FileName));
                IO.Put_Line("File size is " & Size_Type'Image(FileSize) & " bytes.");
        else
                IO.Put_Line("File '" & To_String(FileName) & "' does not exist.");
        end if;
exception
        when Constraint_Error =>
                IO.Put_Line(Cmd.Command_Name & " requires at least 1 argument.");
        when ADA.IO_EXCEPTIONS.NAME_ERROR =>
                null;
end FileInfo;