Use full command line for converting file formats

and no longer rely on pstoedit being the only tool used

Use ps2pdf from GhostScript (which should already be needed by pstoedit)
for PDF as it supports keeping the page size from the eps file

boxes/formats.py

@@ -26,6 +26,7 @@ from boxes.drawing import SVGSurface, PSSurface, LBRN2Surface, Context
 class Formats:
 
     pstoedit_candidates = ["/usr/bin/pstoedit", "pstoedit", "pstoedit.exe"]
+    ps2pdf_candidates = ["/usr/bin/ps2pdf", "ps2pdf", "ps2pdf.exe"]
 
     _BASE_FORMATS = ['svg', 'svg_Ponoko', 'ps', 'lbrn2']
 
@@ -34,11 +35,11 @@ class Formats:
         "svg_Ponoko": None,
         "ps": None,
         "lbrn2": None,
-        "dxf": "-flat 0.1 -f dxf:-mm".split(),
-        "gcode": "-f gcode".split(),
-        "plt": "-f plot-hpgl".split(),
-        "ai": "-f ps2ai".split(),
-        "pdf": "-f pdf".split(),
+        "dxf": "{pstoedit} -flat 0.1 -f dxf:-mm {input} {output}",
+        "gcode": "{pstoedit} -f gcode {input} {output}",
+        "plt": "{pstoedit} -f plot-hpgl {input} {output}",
+        "ai": "{pstoedit} -f ps2ai {input} {output}",
+        "pdf": "{ps2pdf} -dEPSCrop {input} {output}",
     }
 
     http_headers = {
@@ -58,6 +59,10 @@ class Formats:
             self.pstoedit = shutil.which(cmd)
             if self.pstoedit:
                 break
+        for cmd in self.ps2pdf_candidates:
+            self.ps2pdf = shutil.which(cmd)
+            if self.ps2pdf:
+                break
 
     def getFormats(self):
         if self.pstoedit:
@@ -79,7 +84,12 @@ class Formats:
 
         if fmt not in self._BASE_FORMATS:
             fd, tmpfile = tempfile.mkstemp(dir=os.path.dirname(filename))
-            cmd = [self.pstoedit] + self.formats[fmt] + [filename, tmpfile]
+            cmd = self.formats[fmt].format(
+                pstoedit=self.pstoedit,
+                ps2pdf=self.ps2pdf,
+                input=filename,
+                output=tmpfile).split()
+
             err = subprocess.call(cmd)
 
             if err: