bookletify now supports piping

README.md

@@ -20,6 +20,7 @@ Questa repository contiene i seguenti script:
     -   trim
     -   diversi tipi di paper size (A4 di default, per poter mandare in stampa senza dover mettere "fit-to-page")
     -   aggiunta di un bordo interno (a sinistra per le pagine dispari, a destra per le pagine pari) per la rilegatura
+    -   pipe da stdin / a stdout
     
     Dipendenze: `PyPDF2`
 

bookletify.py

@@ -1,6 +1,8 @@
 #!/usr/bin/env python3
 
 import os
+import sys
+import io
 import argparse
 from PyPDF2 import PageObject, PdfReader, PdfWriter, PaperSize, Transformation
 
@@ -13,19 +15,28 @@ def main():
         size on A4 paper"""
     
     parser = argparse.ArgumentParser(prog=PROGRAM_NAME, description=DESCRIPTION)
-    parser.add_argument('filename')
+    parser.add_argument('input',
+                        help="""name of the input file to bookletify. Use '-'
+                            to read file from stdin""")
+    parser.add_argument('output',
+                        help="""name of the output file to write to. Use '-' to
+                            write to stdout""")
     parser.add_argument('-q', '--quiet',
                         action='store_true',
-                        help='suppress stdout')
+                        help="""suppress stdout. Not suppressed if the flag
+                            this flag is absent. Automatically suppressed if
+                            output is '-' (see output), to avoid broken
+                            pdfs""")
     parser.add_argument('-s', '--size',
                         action='store',
-                        choices=['A0', 'A1', 'A2', 'A3', 'A4', 'A5', 'A6', 'A7', 'A8', 'C4'],
+                        choices=['A0', 'A1', 'A2', 'A3', 'A4', 'A5',
+                                'A6', 'A7', 'A8', 'C4'],
                         default='A4',
                         metavar='SIZE',
                         help="""set final paper size. Possible values: 'A0',
                             ..., 'A8' or 'C4'. Default value is 'A4'""")
     parser.add_argument('-b', '--binding-margin',
-                        default=10,
+                        default=8.0,
                         type=float,
                         metavar='MARGIN',
                         help="""internal margin for the binding, expressed in
@@ -36,7 +47,7 @@ def main():
                             decreasing this margin does not trim any content on
                             the final pdf, the content gets scaled down (or up)
                             to fit to the final width minus the binding margin.
-                            Default value is 10""")
+                            Default value is 8""")
     parser.add_argument('-t', '--trim',
                         default=[0,0,0,0],
                         type=float,
@@ -54,21 +65,25 @@ def main():
     
     args = parser.parse_args()
 
+    if args.output == '-':
+        # If output is written to stdout, suppress other stdout output such as
+        # current state of the program and progress bars
+        args.quiet = True
+
     info = lambda text='', end='\n': print(text, end=end)
     if args.quiet:
         info = lambda text='', end='\n': None
 
     prog = lambda curr, max: info(f"\r{curr} / {max}", '\n' if curr == max else '')
 
-    input_name = args.filename
-    if not os.path.isfile(input_name):
-        print(f'file {input_name} does not exist')
-        exit(1)
-    
-    output_name = f'{input_name}-rearranged'
-    if (input_name.endswith('.pdf')):
-        output_name = f'{input_name[0:-4]}-rearranged.pdf'
-    
+    reader = None
+    if args.input == '-':
+        reader = PdfReader(sys.stdin.buffer)
+    else:
+        if not os.path.isfile(args.input):
+            print(f'file {args.input} does not exist')
+            exit(1)
+        reader = PdfReader(args.input)
 
     fullwidth = getattr(PaperSize, args.size).width
     fullheight = getattr(PaperSize, args.size).height
@@ -76,7 +91,10 @@ def main():
     smallheight = fullwidth
     # Convert mm to pixels at 72 dpi
     bindingwidth = args.binding_margin * 72.0 / 25.4
-    smallblank = PageObject.create_blank_page(width=smallwidth - bindingwidth, height=smallheight)
+    smallblank = PageObject.create_blank_page(
+            width=smallwidth - bindingwidth,
+            height=smallheight
+        )
 
     tt = args.trim[0] * 72.0 / 25.4
     tr = args.trim[1] * 72.0 / 25.4
@@ -84,11 +102,9 @@ def main():
     tl = args.trim[3] * 72.0 / 25.4
     
     # Read the input
-    reader = PdfReader(input_name)
+    info("Reading...")
     n = len(reader.pages)
     pages = []
-
-    info("Reading...")
     for i in range(n):
         prog(i, n)
         pages.append(reader.pages[i])
@@ -143,7 +159,13 @@ def main():
     prog(int(m/2), int(m/2))
 
     info("\nSaving...")
-    output.write(output_name)
+    if args.output == '-':
+        data = io.BytesIO()
+        output.write(data)
+        sys.stdout.buffer.write(data.getvalue())
+    else:
+        output.write(args.output)
+
     info("\nDone!")
 
 if __name__ == "__main__":