You can get this by looking at the source code of these tools. Most of them are scripts, which compile a list of Ghostscript options depending on their command line options and execute it at the end. In order to get the
$OPTIONS variables etc. decoded automatically you can make a copy of these scripts and add an
echo before the final command so it is printed in the terminal and not executed. An even simpler alternative is to start them using
$SHELL -x script --args which is the shell debug mode (at least for
bash) which prints all executed commands.
For your 1. I get:
gs -P- -dSAFER -q -P- -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sstdout=%stderr -sOutputFile=input.pdf -P- -dSAFER -c .setpdfwrite -f input.ps
Number 2. is a Perl script and is only using GS for the BBox extraction (as my
fixbb script does I mentioned in your other question):
gs -sDEVICE=bbox -dBATCH -dNOPAUSE -c save pop -f input.pdf
Number 3. is a program not a script and uses
libpoppler internally to do the conversion, not Ghostscript.
Number 4. again simply uses Ghostscript for BBox extraction which is then placed into the otherwise unchanged file. Here the BBox is written to a temp file first.
"gs" -dNOPAUSE -dBATCH -sDEVICE=bbox -c "> setpagedevice" -f "/tmp/gsviewnIk3kp"
Number 5 uses (displayed using the
gs -q -dNOPAUSE -dSAFER -sDEVICE=pdfwrite -sOutputFile=input.pdf -dPDFSETTINGS=/prepress -dMaxSubsetPct=100 -dSubsetFonts=true -dEmbedAllFonts=true -dAutoRotatePages=/None - -c quit