PRINT Statement
Syntax
Syntax: PRINT expr [; expr ...]
Source: pb_cg_emit_print_expr (pb_codegen.c:5674)
Description
Outputs text, numbers, or string expressions to the console using the Windows API WriteFile. Handles integers, floating-point values, and string data. Each expression is formatted and written in sequence. The PRINT statement is the primary means of console I/O and is essential for debugging output, status logging, and interactive programs.
Parameters
| Parameter | Description |
|---|
expr | Any expression to output (numeric literal, variable, string, or expression). Multiple expressions are supported. |
; (semicolon separator) | Placed between expressions to suppress a newline. The next PRINT or expression continues on the same line. |
| (no trailing semicolon) | A PRINT statement ending without ; automatically appends a carriage return + line feed (CRLF). |
PRINT (alone) | A bare PRINT with no expression outputs a blank line (just CRLF). |
Example
FUNCTION PBMAIN() AS LONG
LOCAL x AS LONG
LOCAL name AS STRING
x = 42
name = "PowerBASIC"
' Print a variable with text
PRINT "The value of x is "; x
' Print multiple items on one line
PRINT "Name: "; name; " Value: "; x
' Print blank line
PRINT
' Print without newline (trailing ;)
PRINT "Loading";
PRINT "..."
PRINT "Done!"
FUNCTION = 0
END FUNCTION
Generated Assembly
Console Output Path
; 1. Format integer via wsprintfA
lea rcx, [rbp - intbuf_offset] ; buffer
lea rdx, [__pb_fmt_i64] ; format "%I64d"
mov r8, rax ; value
call [__imp_wsprintfA] ; wsprintfA(buf, fmt, val)
mov [rbp - print_len_offset], rax ; save length
; 2. Write to console via WriteFile
mov rcx, -11 ; STD_OUTPUT_HANDLE
call [__imp_GetStdHandle]
mov [rbp - written_offset], rax
mov rcx, [rbp - written_offset] ; hFile
mov rdx, [rbp - print_ptr_offset] ; lpBuffer
mov r8, [rbp - print_len_offset] ; nBytesToWrite
lea r9, [rbp - written_offset] ; lpBytesWritten
mov [rsp + 32], 0 ; lpOverlapped = NULL
call [__imp_WriteFile]
String Output
; String address -> RDX, length -> R8 via pb_cg_emit_string_address_len
; Then same WriteFile path as above
Newline
lea rdx, [__pb_crlf] ; "\r\n" in .rdata
mov r8, 2 ; 2 bytes
; then WriteFile
Float Output
; Format float to string first
lea r8, [rbp - intbuf_offset] ; buffer
mov rdx, 15 ; precision
call [__imp__gcvt] ; _gcvt(value, 15, buf)
mov [rbp - print_ptr_offset], rax
mov rcx, rax
call [__imp_lstrlenA]
mov [rbp - print_len_offset], rax
; then WriteFile
Imported WinAPI Functions
| Function | DLL | Purpose |
|---|
GetStdHandle | kernel32.dll | Get console output handle (STD_OUTPUT_HANDLE = -11) |
WriteFile | kernel32.dll | Write bytes to console/file |
wsprintfA | user32.dll | Format integer to string buffer |
lstrlenA | kernel32.dll | Get ANSI string length |
_gcvt | msvcrt.dll | Convert float to string |