raw_printer/
lib.rs

1#[cfg(test)]
2mod tests {
3    use super::*;
4
5    #[test]
6    #[cfg(target_os = "linux")]
7    fn test_write_to_device_linux() {
8        let result = write_to_device("/dev/usb/lp0", "^FDhello world", Some("Test Document"));
9        assert!(result.is_ok());
10    }
11
12    #[test]
13    #[cfg(target_os = "windows")]
14    fn test_write_to_device_windows() {
15        let result = write_to_device("ZDesigner ZD220-203dpi ZPL", "^FDhello world", Some("Test Document"));
16        assert!(result.is_ok());
17    }
18}
19
20/// # Platform-specific Behavior
21///
22/// This function returns a result containing the size of bytes written on success or an error.
23///
24/// - On Linux and Windows, the result type is `Result<usize, Error>`.
25/// - Note: On Windows, the original bytes written are u32 but cast to usize.
26///
27/// # Examples
28///
29/// ```
30/// let zpl = "^FDhello world";
31/// let printer = "/dev/usb/lp0";
32/// let result = raw_printer::write_to_device(printer, zpl, Some("My Custom Document"));
33/// 
34/// assert!(result.is_ok());
35/// 
36/// ```
37#[cfg(target_os = "linux")]
38pub fn write_to_device(printer: &str, payload: &str, _document_name: Option<&str>) -> Result<usize, std::io::Error> {
39    use std::fs::OpenOptions;
40    use std::io::Write;
41
42    let device_path = OpenOptions::new().write(true).open(printer);
43
44    match device_path {
45        Ok(mut device) => {
46            let bytes_written = device.write(payload.as_bytes())?;
47            Ok(bytes_written)
48        }
49        Err(e) => Err(std::io::Error::new(std::io::ErrorKind::Other, e)),
50    }
51}
52
53#[cfg(target_os = "windows")]
54pub fn write_to_device(printer: &str, payload: &str, document_name: Option<&str>) -> Result<usize, std::io::Error> {
55    use std::ffi::CString;
56    use std::ptr;
57    use windows::Win32::Foundation::HANDLE;
58    use windows::Win32::Graphics::Printing::{
59        ClosePrinter, EndDocPrinter, EndPagePrinter, OpenPrinterA, StartDocPrinterA,
60        StartPagePrinter, WritePrinter, DOC_INFO_1A, PRINTER_ACCESS_USE, PRINTER_DEFAULTSA,
61    };
62
63    let printer_name = CString::new(printer).unwrap_or_default(); // null-terminated string
64    let mut printer_handle: HANDLE = HANDLE(std::ptr::null_mut());
65
66    // Open the printer
67    unsafe {
68        let pd = PRINTER_DEFAULTSA {
69            pDatatype: windows::core::PSTR(ptr::null_mut()),
70            pDevMode: ptr::null_mut(),
71            DesiredAccess: PRINTER_ACCESS_USE,
72        };
73
74        if OpenPrinterA(
75            windows::core::PCSTR(printer_name.as_bytes().as_ptr()),
76            &mut printer_handle,
77            Some(&pd),
78        )
79        .is_ok()
80        {
81            let doc_name = document_name.unwrap_or("Print Job");
82            let doc_name_cstring = CString::new(doc_name).unwrap_or_default();
83            
84            let doc_info = DOC_INFO_1A {
85                pDocName: windows::core::PSTR(doc_name_cstring.as_ptr() as *mut u8),
86                pOutputFile: windows::core::PSTR::null(),
87                pDatatype: windows::core::PSTR("RAW\0".as_ptr() as *mut u8),
88            };
89
90            // Start the document
91            let job = StartDocPrinterA(printer_handle, 1, &doc_info as *const _ as _);
92            if job == 0 {
93                return Err(std::io::Error::from(windows::core::Error::from_win32()));
94            }
95
96            // Start the page
97            if !StartPagePrinter(printer_handle).as_bool() {
98                return Err(std::io::Error::from(windows::core::Error::from_win32()));
99            }
100
101            let buffer = payload.as_bytes();
102
103            let mut bytes_written: u32 = 0;
104            if !WritePrinter(
105                printer_handle,
106                buffer.as_ptr() as _,
107                buffer.len() as u32,
108                &mut bytes_written,
109            )
110            .as_bool()
111            {
112                return Err(std::io::Error::from(windows::core::Error::from_win32()));
113            }
114
115            // End the page and document
116            let _ = EndPagePrinter(printer_handle);
117            let _ = EndDocPrinter(printer_handle);
118            let _ = ClosePrinter(printer_handle);
119            return Ok(bytes_written as usize);
120        } else {
121            return Err(std::io::Error::from(windows::core::Error::from_win32()));
122        }
123    }
124}
raw_printer/lib.rs

raw_printer/
lib.rs
