Because Linux more way to install the software, so there is no common approach can be found whether certain software is installed. Summed up several categories:
1, rpm package installed, you can use rpm -qa see, if you want to find a software package is installed, use rpm -qa | grep "or the name of the software package."
[root@hexuweb102 ~] rpm -qa | grep ruby
2, with deb packages installed, can be seen with the dpkg -l. If it is to find the specified packages, with dpkg -l | grep "or the name of the software package";
[root@hexuweb102~]dpkg-l|grepruby
3, yum install method, you can use yum list installed look, if it is to find the specified package, added to the command | grep "or the name of the software package name";
[root@hexuweb102 ~] yum list installed | grep ruby
4. If the source package is compiled and installed their own, such as .tar.gz or tar.bz2 form, this can only see whether an executable file exists,
The above two methods can not see the source of this form of installation packages. If the user is root installation, executable programs are in / sbin: under / usr / bin directory.
Description: which is Redhat rpm yum-based linux package management command, dpkg series is debian package management commands