yao@ubuntu:~/perl$ xpdf-2.01/xpdf/pdftotext 1.pdf
bash: xpdf-2.01/xpdf/pdftotext: Permission denied
yao@ubuntu:~/perl$ xpdf-2.01/xpdf/pdftotext 2.pdf
bash: xpdf-2.01/xpdf/pdftotext: Permission denied
yao@ubuntu:~/perl$ cd xpdf-2.01
yao@ubuntu:~/perl/xpdf-2.01$ cd xpdf
yao@ubuntu:~/perl/xpdf-2.01/xpdf$ pdftotext /home/yao/perl/1.pdf