Determine Linux distribution

I am trying to determine what flavor of linux server is running. I am not trying to determine the kernel version - but rater the distributor.

gcc is installed, and in the version output, it says RedHat

# gcc --version
gcc (GCC) 3.4.6 20060404 (Red Hat 3.4.6-11)

Does this mean I can safely assume my server is a RedHat server. Is there a better - 100% bulletproof method to find this out? Also for other linux flavors - not just this server?

Edit: contents of /etc/ in case it helps - but I would like a solution that works for other versions of linux too.

# ls /etc/
./              backupmxhosts  domainusers     host.conf     localdomains  mailips        pam.d/      relayhosts               shadow              trustedmailhosts
../             bashrc*        exim.conf       inputrc       localtime     man.config     passwd      resolv.conf              skipsmtpcheckhosts  userdomains
DIR_COLORS      cron.deny      exim.pl         ld.so.cache   lynx.cfg      mtab           profile     secondarymx              spammeripblocks     vimrc
aliases         demodomains    exim.pl.local*  ld.so.conf    mail/         my.cnf         profile.d/  senderverifybypasshosts  sudoers
antivirus.exim  demouids       group           localaliases  mailhelo      nsswitch.conf  protocols   services                 termcap

I have no *release or *versionfiles in /etc/

# ls /etc*release; ls /etc/*version
/bin/ls: /etc/*release: No such file or directory
/bin/ls: /etc/*version: No such file or directory

I tried LSB

# lsb_release -a
LSB Version:
Distributor ID: n/a
Description:    (none)
Release:        n/a
Codename:       n/a

Also - I guess I am inside a chroot jail (not really sure what that is) which could likely be the cause for this issue.

Updated:

I think this does it for me. I think I can safely assume I am using cent-os.

# cat /proc/version
Linux version 2.6.9-103.plus.c4smp ([email protected]) (gcc version 3.4.6 20060404 (Red Hat 3.4.6-11)) #1 SMP Wed Dec 21 16:17:23 EST 2011

Solution 1:

cat /proc/version

Examples:

1. Ubuntu:

   $ cat /proc/version
   Linux version 3.11.0-13-generic (buildd@roseapple) (gcc version 4.8.1 \
   (Ubuntu/Linaro 4.8.1-10ubuntu8) ) #20-Ubuntu SMP Wed Oct 23 07:38:26 UTC 2013
   

2. Red Hat / CentOS:

   $ cat /proc/version
   Linux version 2.6.32-220.13.1.el6.x86_64 ([email protected]) \
   (gcc version 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC) ) #1 SMP Tue Apr 17 23:56:34 BST 2012
   

See also How To Know Which Linux Distribution You Are Using?

Solution 2:

On most modern Linux distros, the following command will give you its information:

lsb_release -a

Solution 3:

/etc/issue might be a good starting point.

More could be found by inspecting the info files for different distributions:

Novell SuSE    /etc/SuSE-release
OpenSuSE       /etc/SuSE-release, /etc/os-release
Red Hat,CentOS /etc/redhat-release, /etc/redhat_version
Fedora         /etc/fedora-release, /etc/redhat-release, /etc/os-release
Slackware      /etc/slackware-release, /etc/slackware-version
Debian         /etc/debian_release, /etc/debian_version
Mandrake       /etc/mandrake-release
Yellow dog     /etc/yellowdog-release
Sun JDS        /etc/sun-release 
Solaris/Sparc  /etc/release 
Gentoo         /etc/gentoo-release
Amazon Linux   /etc/system-release
PLD Linux      /etc/pld-release, /etc/os-release
ArchLinux      /etc/arch-release, /etc/os-release

See Unix forum for more details.

Solution 4:

If /etc/issue is missing, there may be one or more /etc/*_release files.

For example, my Ubuntu system has /etc/lsb-release:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=11.04
DISTRIB_CODENAME=natty
DISTRIB_DESCRIPTION="Ubuntu 11.04"

A friend's CentOS system (based on Red Hat) has /etc/redhat-release:

CentOS release 5.6 (Final)

I don't know how universal this is.