一、如何得知共安装了多少个软件包
[root@localhost ~]# rpm -qa | wc -l
例如：
[root@localhost ~]# rpm -qa | wc -l
217
二、如何得知安装了那些软件包
[root@localhost ~]# rpm -qa | sort
例如：
[root@localhost ~]# rpm -qa | sort
acl-2.2.49-6.el6.x86_64
aic94xx-firmware-30-2.el6.noarch
atmel-firmware-1.3-7.el6.noarch
attr-2.4.44-7.el6.x86_64
audit-2.2-2.el6.x86_64
audit-libs-2.2-2.el6.x86_64
authconfig-6.1.12-13.el6.x86_64
b43-openfwwf-5.2-4.el6.noarch
basesystem-10.0-4.el6.noarch
bash-4.1.2-15.el6_4.x86_64
bfa-firmware-3.2.21.1-2.el6.noarch
binutils-2.20.51.0.2-5.36.el6.x86_64
bzip2-1.0.5-7.el6_0.x86_64
bzip2-libs-1.0.5-7.el6_0.x86_64
ca-certificates-2013.1.94-65.0.el6.noarch
centos-release-6-5.el6.centos.11.1.x86_64
checkpolicy-2.0.22-1.el6.x86_64
chkconfig-1.3.49.3-2.el6_4.1.x86_64
coreutils-8.4-31.el6.x86_64
coreutils-libs-8.4-31.el6.x86_64
cpio-2.10-11.el6_3.x86_64
cracklib-2.8.16-4.el6.x86_64
cracklib-dicts-2.8.16-4.el6.x86_64
cronie-1.4.4-12.el6.x86_64
cronie-anacron-1.4.4-12.el6.x86_64
crontabs-1.10-33.el6.noarch
curl-7.19.7-37.el6_4.x86_64
cyrus-sasl-2.1.23-13.el6_3.1.x86_64
cyrus-sasl-lib-2.1.23-13.el6_3.1.x86_64
dash-0.5.5.1-4.el6.x86_64
db4-4.7.25-18.el6_4.x86_64
db4-utils-4.7.25-18.el6_4.x86_64
dbus-glib-0.86-6.el6.x86_64
dbus-libs-1.2.24-7.el6_3.x86_64
device-mapper-1.02.79-8.el6.x86_64
device-mapper-event-1.02.79-8.el6.x86_64
device-mapper-event-libs-1.02.79-8.el6.x86_64
device-mapper-libs-1.02.79-8.el6.x86_64
device-mapper-persistent-data-0.2.8-2.el6.x86_64
dhclient-4.1.1-38.P1.el6.centos.x86_64
dhcp-common-4.1.1-38.P1.el6.centos.x86_64
diffutils-2.8.1-28.el6.x86_64
dracut-004-335.el6.noarch
dracut-kernel-004-335.el6.noarch
e2fsprogs-1.41.12-18.el6.x86_64
e2fsprogs-libs-1.41.12-18.el6.x86_64
efibootmgr-0.5.4-11.el6.x86_64
elfutils-libelf-0.152-1.el6.x86_64
ethtool-3.5-1.el6.x86_64
expat-2.0.1-11.el6_2.x86_64
file-5.04-15.el6.x86_64
file-libs-5.04-15.el6.x86_64
filesystem-2.4.30-3.el6.x86_64
findutils-4.4.2-6.el6.x86_64
fipscheck-1.2.0-7.el6.x86_64
fipscheck-lib-1.2.0-7.el6.x86_64
gamin-0.1.10-9.el6.x86_64
gawk-3.1.7-10.el6.x86_64
gdbm-1.8.0-36.el6.x86_64
glib2-2.26.1-3.el6.x86_64
glibc-2.12-1.132.el6.x86_64
glibc-common-2.12-1.132.el6.x86_64
gmp-4.3.1-7.el6_2.2.x86_64
gnupg2-2.0.14-6.el6_4.x86_64
gpgme-1.1.8-3.el6.x86_64
grep-2.6.3-4.el6.x86_64
groff-1.18.1.4-21.el6.x86_64
grub-0.97-83.el6.x86_64
grubby-7.0.15-5.el6.x86_64
gzip-1.3.12-19.el6_4.x86_64
hwdata-0.233-9.1.el6.noarch
info-4.13a-8.el6.x86_64
initscripts-9.03.40-2.el6.centos.x86_64
iproute-2.6.32-31.el6.x86_64
iptables-1.4.7-11.el6.x86_64
iptables-ipv6-1.4.7-11.el6.x86_64
iputils-20071127-17.el6_4.2.x86_64
ipw2100-firmware-1.3-11.el6.noarch
ipw2200-firmware-3.1-4.el6.noarch
ivtv-firmware-20080701-20.2.noarch
iwl1000-firmware-39.31.5.1-1.el6.noarch
iwl100-firmware-39.31.5.1-1.el6.noarch
iwl3945-firmware-15.32.2.9-4.el6.noarch
iwl4965-firmware-228.61.2.24-2.1.el6.noarch
iwl5000-firmware-8.83.5.1_1-1.el6_1.1.noarch
iwl5150-firmware-8.24.2.2-1.el6.noarch
iwl6000-firmware-9.221.4.1-1.el6.noarch
iwl6000g2a-firmware-17.168.5.3-1.el6.noarch
iwl6050-firmware-41.28.5.1-2.el6.noarch
kbd-1.15-11.el6.x86_64
kbd-misc-1.15-11.el6.noarch
kernel-2.6.32-431.el6.x86_64
kernel-firmware-2.6.32-431.el6.noarch
keyutils-libs-1.4-4.el6.x86_64
krb5-libs-1.10.3-10.el6_4.6.x86_64
less-436-10.el6.x86_64
libacl-2.2.49-6.el6.x86_64
libattr-2.4.44-7.el6.x86_64
libblkid-2.17.2-12.14.el6.x86_64
libcap-2.16-5.5.el6.x86_64
libcap-ng-0.6.4-3.el6_0.1.x86_64
libcom_err-1.41.12-18.el6.x86_64
libcurl-7.19.7-37.el6_4.x86_64
libdrm-2.4.45-2.el6.x86_64
libertas-usb8388-firmware-5.110.22.p23-3.1.el6.noarch
libffi-3.0.5-3.2.el6.x86_64
libgcc-4.4.7-4.el6.x86_64
libgcrypt-1.4.5-11.el6_4.x86_64
libgpg-error-1.7-4.el6.x86_64
libidn-1.18-2.el6.x86_64
libnih-1.0.1-7.el6.x86_64
libpciaccess-0.13.1-2.el6.x86_64
libselinux-2.0.94-5.3.el6_4.1.x86_64
libselinux-utils-2.0.94-5.3.el6_4.1.x86_64
libsemanage-2.0.43-4.2.el6.x86_64
libsepol-2.0.41-4.el6.x86_64
libss-1.41.12-18.el6.x86_64
libssh2-1.4.2-1.el6.x86_64
libstdc++-4.4.7-4.el6.x86_64
libtasn1-2.3-3.el6_2.1.x86_64
libudev-147-2.51.el6.x86_64
libusb-0.1.12-23.el6.x86_64
libuser-0.56.13-5.el6.x86_64
libutempter-1.1.5-4.1.el6.x86_64
libuuid-2.17.2-12.14.el6.x86_64
libxml2-2.7.6-14.el6.x86_64
logrotate-3.7.8-17.el6.x86_64
lua-5.1.4-4.1.el6.x86_64
lvm2-2.02.100-8.el6.x86_64
lvm2-libs-2.02.100-8.el6.x86_64
m4-1.4.13-5.el6.x86_64
make-3.81-20.el6.x86_64
MAKEDEV-3.24-6.el6.x86_64
mingetty-1.08-5.el6.x86_64
module-init-tools-3.9-21.el6_4.x86_64
mysql-libs-5.1.71-1.el6.x86_64
ncurses-5.7-3.20090208.el6.x86_64
ncurses-base-5.7-3.20090208.el6.x86_64
ncurses-libs-5.7-3.20090208.el6.x86_64
net-tools-1.60-110.el6_2.x86_64
newt-0.52.11-3.el6.x86_64
newt-python-0.52.11-3.el6.x86_64
nspr-4.10.0-1.el6.x86_64
nss-3.15.1-15.el6.x86_64
nss-softokn-3.14.3-9.el6.x86_64
nss-softokn-freebl-3.14.3-9.el6.x86_64
nss-sysinit-3.15.1-15.el6.x86_64
nss-tools-3.15.1-15.el6.x86_64
nss-util-3.15.1-3.el6.x86_64
openldap-2.4.23-32.el6_4.1.x86_64
openssh-5.3p1-94.el6.x86_64
openssh-server-5.3p1-94.el6.x86_64
openssl-1.0.1e-15.el6.x86_64
p11-kit-0.18.5-2.el6.x86_64
p11-kit-trust-0.18.5-2.el6.x86_64
pam-1.1.1-17.el6.x86_64
passwd-0.77-4.el6_2.2.x86_64
pciutils-libs-3.1.10-2.el6.x86_64
pcre-7.8-6.el6.x86_64
pinentry-0.7.6-6.el6.x86_64
pkgconfig-0.23-9.1.el6.x86_64
plymouth-0.8.3-27.el6.centos.x86_64
plymouth-core-libs-0.8.3-27.el6.centos.x86_64
plymouth-scripts-0.8.3-27.el6.centos.x86_64
policycoreutils-2.0.83-19.39.el6.x86_64
popt-1.13-7.el6.x86_64
postfix-2.6.6-2.2.el6_1.x86_64
procps-3.2.8-25.el6.x86_64
psmisc-22.6-15.el6_0.1.x86_64
pth-2.0.7-9.3.el6.x86_64
pygpgme-0.1-18.20090824bzr68.el6.x86_64
python-2.6.6-51.el6.x86_64
python-iniparse-0.3.1-2.1.el6.noarch
python-libs-2.6.6-51.el6.x86_64
python-pycurl-7.19.0-8.el6.x86_64
python-urlgrabber-3.9.1-9.el6.noarch
ql2100-firmware-1.19.38-3.1.el6.noarch
ql2200-firmware-2.02.08-3.1.el6.noarch
ql23xx-firmware-3.03.27-3.1.el6.noarch
ql2400-firmware-7.00.01-1.el6.noarch
ql2500-firmware-7.00.01-1.el6.noarch
readline-6.0-4.el6.x86_64
redhat-logos-60.0.14-12.el6.centos.noarch
rootfiles-8.1-6.1.el6.noarch
rpm-4.8.0-37.el6.x86_64
rpm-libs-4.8.0-37.el6.x86_64
rpm-python-4.8.0-37.el6.x86_64
rsyslog-5.8.10-8.el6.x86_64
rt61pci-firmware-1.2-7.el6.noarch
rt73usb-firmware-1.8-7.el6.noarch
sed-4.2.1-10.el6.x86_64
selinux-policy-3.7.19-231.el6.noarch
selinux-policy-targeted-3.7.19-231.el6.noarch
setup-2.8.14-20.el6_4.1.noarch
shadow-utils-4.1.4.2-13.el6.x86_64
shared-mime-info-0.70-4.el6.x86_64
slang-2.2.1-1.el6.x86_64
sqlite-3.6.20-1.el6.x86_64
sudo-1.8.6p3-12.el6.x86_64
system-config-firewall-base-1.2.27-5.el6.noarch
sysvinit-tools-2.87-5.dsf.el6.x86_64
tar-1.23-11.el6.x86_64
tcp_wrappers-libs-7.6-57.el6.x86_64
tzdata-2013g-1.el6.noarch
udev-147-2.51.el6.x86_64
upstart-0.6.5-12.el6_4.1.x86_64
ustr-1.0.4-9.1.el6.x86_64
util-linux-ng-2.17.2-12.14.el6.x86_64
vim-minimal-7.2.411-1.8.el6.x86_64
which-2.19-6.el6.x86_64
xorg-x11-drv-ati-firmware-7.1.0-3.el6.noarch
xz-libs-4.999.9-0.3.beta.20091007git.el6.x86_64
yum-3.2.29-40.el6.centos.noarch
yum-metadata-parser-1.1.2-16.el6.x86_64
yum-plugin-fastestmirror-1.1.30-14.el6.noarch
zd1211-firmware-1.4-4.el6.noarch
zlib-1.2.3-29.el6.x86_64
