ADA Program to print a string entered by user

Program

With Gnat.IO; use Gnat.IO;
procedure gnatiostring is
	s : String (1 .. 100);
	i : Integer;
begin
	Put ("Enter a String: ");
	Get_Line (s, i);
	Put ("Your String is : ");
	Put_Line (s (1 .. i));
end;

This program showcases basic string handling in Ada. It reads a string input from the user and prints it.

1. With Gnat.IO; use Gnat.IO;

   • Imports the Gnat.IO package, which provides functions for input and output.
   • use Gnat.IO; allows direct usage of procedures like Put, Put_Line, and Get_Line.

2. procedure gnatiostring is

   • Defines the procedure gnatiostring, which acts as the main program.

3. s : String (1 .. 100);

   • Declares a string variable s with a fixed size of 100 characters.
   • The index (1 .. 100) defines a string of length 100.

4. i : Integer;

   • Declares an integer variable i to store the actual length of the input string.

5. begin

   • Marks the start of the executable code.

6. Put ("Enter a String: ");

   • Displays a prompt asking the user to enter a string.

7. Get_Line (s, i);

   • Reads a line of text from the user and stores it in s.
   • The variable i stores the actual number of characters entered.

8. Put ("Your String is : ");

   • Displays the message "Your String is : ".

9. Put_Line (s (1 .. i));

   • Prints the actual entered string from index 1 to i (ignoring unused space).

10. end;

• Marks the end of the program.

Key Features:

• Uses Gnat.IO for input and output.
• Reads an entire string using Get_Line.
• Stores actual length to avoid printing extra spaces.
• Efficiently handles user input in Ada.

Output

$ gnat make gnatiostring.adb
gcc -c gnatiostring.adb
gnatbind -x gnatiostring.ali
gnatlink gnatiostring.ali
$ ./gnatiostring
Enter a String: Welcome
Your String is : Welcome