I have seen many questions about Running
Linux version 2.6.32-604.30.3.lve1.3.63.el6.x86_64 (firstname.lastname@example.org) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-16) (GCC) ) #1 SMP Sun Sep 27 06:34:10 EDT 2015
exec('yum install poppler-utils',$buffer);
install pdftotext under RedHat / RHEL / Fedora / CentOS Linux
pdftotext is installed using poppler-utils package under various Linux
# yum install poppler-utils
OR use the following under Debian / Ubuntu Linux
$ sudo apt-get install poppler-utils
You won't have sudo / root privileges on shared hosting to install files. The only option is to contact your hosting company and to ask for them to install it on the server.
You cant run
exec on commands you don't have access to the function e.g.