Ghostscript: PDF total pages - api

Question

I'm using Ghostscript library API (wrapping from C#) to print PDF documents from my application.
With the '-dFirstPage' and '-dLastPage' parameters I'm able to select an range of pages to be printed, but how about the total number of a PDF's pages?
It is not very nice to allow a user to select a page interval from 2 to 10 when, let me say, the PDF document has only 4 pages.
Consider that I'm using Ghostscript library through the gsapi_init_with_args API library call.

Answer 1

Ghostscript can count and display the number of pages of a PDF on stdout. The commandline is
gswin32c ^
-q ^
-dNODISPLAY ^
-c "(input.pdf) (r) file runpdfbegin pdfpagecount = quit"
Here all the -c "..." stuff is a PostScript commandline snippet (using a few GS internal command extensions). And input.pdf is the PDF filename (could also be a full path like (c:/path/to/my.pdf)).
However, a better and faster tool for this kind of job would be to use pdfinfo (part of the XPDF-utilities, also available on Windows).
Update:
#ebyrob wants to know if one can modify my example command line so that it also displays the PDF in a single operation. Try this:
gswin32c ^
-q ^
-c "(input.pdf) (r) file runpdfbegin pdfpagecount =" ^
-f input.pdf
Well, it's not a single operation -- it's just two different operations in a single commandline.

Answer 2

For people having issues in ghostscript >9.50 add --permit-file-read=input.pdf

Answer 3

I tried to make this script:
gswin32c ^
-q ^
-c "(input.pdf) (r) file runpdfbegin pdfpagecount =" ^
-f input.pdf
work in a c# wrapped solution and kept getting error "/undefinedfilename". In this case ensure that your filepath has Slashes "/" as DirectorySeperator and not Backslashes "\". I know Kurt Pfeifle already wrote it, but it happened to me i just overlooked it.

Answer 4

In Windows systems:
"path to gs exec" -q -dNODISPLAY -dNOSAFER --permit-file-read="path to
your file" -c "(""path to your file"") (r) file runpdfbegin
pdfpagecount = quit"
Remarks:
Just change where is 'path to...' with your path, leave the rest as is.
On the -c path you must use double slashes or unix like ones. Ex: C:\\youfile.pdf (good), C:/youfile.pdf (good), C:\yourfile.pdf (bad).
Example:
path: C:\Temp\Some Folder\myFile.pdf
gs path: C:\Temp\Some Folder\gs\bin\gswin64c.exe
path -c 1: C:\\Temp\\Some Folder\\myFile.pdf
path -c 2: C:/Temp/Some Folder/myFile.pdf
Commands:
"C:\Temp\Some Folder\gs\bin\gswin64c.exe" -q -dNODISPLAY -dNOSAFER --permit-file-read="C:\Temp\Some Folder\myFile.pdf" -c "(""C:\\Temp\\Some Folder\\myFile.pdf"") (r) file runpdfbegin pdfpagecount = quit"
"C:\Temp\Some Folder\gs\bin\gswin64c.exe" -q -dNODISPLAY -dNOSAFER --permit-file-read="C:\Temp\Some Folder\myFile.pdf" -c "(""C:/Temp/Some Folder/myFile.pdf"") (r) file runpdfbegin pdfpagecount = quit"

Answer 5

To sum up some of the above separate comments for windows users to avoid needing to alter between / and \\ , to show the total number of pages can be set as a shortcut for drag and drop or "sendTo", by first switching to a working directory.
#echo off & cd /d "%~dp1" & "C:\path to gs\bin\gs.exe" -q --permit-file-read="%~nx1" -c "(%~nx1) (r) file runpdfbegin pdfpagecount = quit" & pause
where gs.exe is one of the windows c(onsole) variants gswin32c.exe or gswin64c.exe
The cd /c "%~dp1" will switch console to quoted file drive path
The full quoted path to "GSwin..c.exe" calls it safely and remotely
-q will suppress (not show) the start message
since version 9.5+ the --permit-file-read="file name" is advised / required
-c "(%~nx1) does not need the quotes for name.xtension
if running a cmd as a shortcut, pause is required to see the result
beware only use on files you trust as your overriding GS -dSAFER restrictions.