A small shell script to convert singlepage A4-sized pdf documents to two pages per sheet using pstools.
#!/bin/bash function switch() { rm -f pdfopt.ps mv pdfopt2.ps pdfopt.ps } pdftops -paper A4 -level3 $1 pdfopt.ps psresize -p a4 pdfopt.ps pdfopt2.ps ; switch psnup -n2 -d1 -pa4 -Pa4 pdfopt.ps pdfopt2.ps ; switch psresize -pa4 pdfopt.ps pdfopt2.ps ; switch psresize -Pa4 pdfopt.ps pdfopt2.ps ; switch ps2ps pdfopt.ps pdfopt2.ps ; switch ps2pdf pdfopt.ps `basename $1 .pdf`_2.pdf rm -f pdfopt.ps