print server for cups (generic pdf set to A6)

appsocket.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+
+import tspl
+import socket
+import logging
+import tempfile
+
+logging.basicConfig(level=logging.DEBUG)
+
+UEL = b'\x1b%-12345X'
+ENTER_PDF = b'@PJL ENTER LANGUAGE = PDF'
+
+def accept_one_job(sock):
+    def read_more_data(data):
+        new_data = sock.recv(1048576)
+        if not len(new_data):
+            logging.error('Received unexpected EOF from client')
+            return
+        data.extend(new_data)
+
+    def consume_up_to(data, marker):
+        while not marker in data:
+            read_more_data(data)
+
+        pos = data.index(marker)
+        before_marker = data[:pos]
+        after_marker = data[pos+len(marker):]
+        return before_marker, after_marker
+
+    data = bytearray()
+
+    _, data = consume_up_to(data, UEL)
+    _, data = consume_up_to(data, ENTER_PDF)
+    pdf_data, _ = consume_up_to(data, UEL)
+    pdf_data = pdf_data.lstrip()
+
+    with tempfile.NamedTemporaryFile(suffix=".pdf") as pdffile:
+        pdffile.write(pdf_data)
+        pdffile.flush()
+        tspl.print_pdf(pdffile.name)
+
+    logging.info('Job complete')
+
+sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+sock.bind(('0.0.0.0', 9100))
+sock.listen()
+
+class ConnectionClosed(Exception):
+    pass
+
+while True:
+    conn, peer = sock.accept()
+    logging.info('New connection from %s' % peer[0])
+
+    try:
+        accept_one_job(conn)
+    except ConnectionClosed:
+        pass
+    except Exception as e:
+        logging.exception(e)
+    finally:
+        conn.close()

tspl.py

@@ -25,7 +25,7 @@ def convert_pdf_scaled(pdfname, max_width, max_height):
     args = ['-scale-to-x', str(max_width), '-scale-to-y', str(max_height)]
     im = convert_pdf(pdfname, args)
 
-    assert im.size[0] <= max_width
+    assert im.size[0] <= max_width + 1
     assert im.size[1] <= max_height
 
     return im
@@ -35,20 +35,24 @@ def label_to_command(image, labelwidth_mm=100, labelheight_mm=150, dpi=203):
     labelwidth = labelwidth_mm / 25.4 * dpi
     labelheight = labelheight_mm / 25.4 * dpi
 
-    assert im.size[0] <= labelwidth
-    assert im.size[1] <= labelheight
+    assert image.size[0] <= labelwidth + 5
+    assert image.size[1] <= labelheight + 5
 
-    paste_x = (labelwidth - im.size[0]) // 2
-    paste_y = (labelheight - im.size[1]) // 2
-    row_bytes = (im.size[0] + 7) // 8
+    paste_x = (labelwidth - image.size[0]) // 2
+    paste_y = (labelheight - image.size[1]) // 2
+    row_bytes = (image.size[0] + 7) // 8
 
-    command = b"SIZE %d mm\r\nCLS\r\nBITMAP %d,%d,%d,%d,0," % (labelwidth_mm, paste_x, paste_y, row_bytes, im.size[1])
+    command = b"SIZE %d mm\r\nCLS\r\nBITMAP %d,%d,%d,%d,0," % (labelwidth_mm, paste_x, paste_y, row_bytes, image.size[1])
     command += image.tobytes()
     command += b"\r\nPRINT 1,1\r\n"
     return command
 
-
-im = convert_pdf_scaled("test.pdf", 800, 1200)
+def print_pdf(filename):
+    im = convert_pdf_scaled(filename, 800, 1200)
     cmd = label_to_command(im)
     with open("/dev/usb/lp0", "r+b") as prn:
         prn.write(cmd)
+
+if __name__ == "__main__":
+    import sys
+    print_pdf(sys.argv[1])