How to uninstall pre-installed previous version and install new

How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

My RHEL6.1 has pre installed gcc (GCC) 4.4.5 20110214 (Red Hat
4.4.5-6). I want to update it to latest version. I don't have red hat
subscription and therefore I'll have to install from source. How can I
uninstall this version and install a more recent version of GCC.

Thanks
Ahsan

Re: How to uninstall pre-installed previous version and install new

[Jonathan Wakely]

On 5 August 2014 04:45, Syed Ahsan Ali Bokhari wrote:
> My RHEL6.1 has pre installed gcc (GCC) 4.4.5 20110214 (Red Hat
> 4.4.5-6). I want to update it to latest version. I don't have red hat
> subscription and therefore I'll have to install from source. How can I
> uninstall this version

"yum erase gcc" but I would advise against doing that.

> and install a more recent version of GCC.

It's a bad idea to replace the system compiler, just install a newer
version in a different path.

Re: How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

Thanks Jonathan for your suggestions.


On Tue, Aug 5, 2014 at 1:37 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 5 August 2014 04:45, Syed Ahsan Ali Bokhari wrote:
>> My RHEL6.1 has pre installed gcc (GCC) 4.4.5 20110214 (Red Hat
>> 4.4.5-6). I want to update it to latest version. I don't have red hat
>> subscription and therefore I'll have to install from source. How can I
>> uninstall this version
>
> "yum erase gcc" but I would advise against doing that.
>
>> and install a more recent version of GCC.
>
> It's a bad idea to replace the system compiler, just install a newer
> version in a different path.



-- 
 Syed Ahsan Ali Bokhari
 Electronic Engineer
 Research & Development Division
 Pakistan Meteorological Department H-8/2, Islamabad.
 Phone # off +92519250361
 Cell # +923155145014
 Fax # +92519250368
 www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Ángel González]

On 05/08/14 10:37, Jonathan Wakely wrote:
> On 5 August 2014 04:45, Syed Ahsan Ali Bokhari wrote:
>> My RHEL6.1 has pre installed gcc (GCC) 4.4.5 20110214 (Red Hat
>> 4.4.5-6). I want to update it to latest version. I don't have red hat
>> subscription and therefore I'll have to install from source. How can I
>> uninstall this version
> "yum erase gcc" but I would advise against doing that.
>
>> and install a more recent version of GCC.
> It's a bad idea to replace the system compiler, just install a newer
> version in a different path.
Specially if you attempt to remove it before having the new one ready,
as you won't be able to install from source (thus compil¡ng) the new 
version
without a working compiler.

Re: How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

Yes I did that before, I removed the gcc and when I tried to build a
new gcc from source it crashed complaining that no C compiler is
present. Isn't it weird that installation of C compiler needs C
compiler as a pre-requisite.?

On Tue, Aug 5, 2014 at 2:32 PM, Ángel González <keisial@gmail.com> wrote:
> On 05/08/14 10:37, Jonathan Wakely wrote:
>>
>> On 5 August 2014 04:45, Syed Ahsan Ali Bokhari wrote:
>>>
>>> My RHEL6.1 has pre installed gcc (GCC) 4.4.5 20110214 (Red Hat
>>> 4.4.5-6). I want to update it to latest version. I don't have red hat
>>> subscription and therefore I'll have to install from source. How can I
>>> uninstall this version
>>
>> "yum erase gcc" but I would advise against doing that.
>>
>>> and install a more recent version of GCC.
>>
>> It's a bad idea to replace the system compiler, just install a newer
>> version in a different path.
>
> Specially if you attempt to remove it before having the new one ready,
> as you won't be able to install from source (thus compil¡ng) the new version
> without a working compiler.
>



-- 
 Syed Ahsan Ali Bokhari
 Electronic Engineer
 Research & Development Division
 Pakistan Meteorological Department H-8/2, Islamabad.
 Phone # off +92519250361
 Cell # +923155145014
 Fax # +92519250368
 www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Jonathan Wakely]

On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
> Yes I did that before, I removed the gcc and when I tried to build a
> new gcc from source it crashed complaining that no C compiler is
> present. Isn't it weird that installation of C compiler needs C
> compiler as a pre-requisite.?

You don't need a compiler to install a C compiler, you need a compiler
to *compile* a C compiler, just like you need a compiler to compile
any program.

If you just want to install gcc you use 'yum' or 'rpm' to do that,
instead of compiling it yourself.

If you want to compile gcc, obviously you need a compiler of some kind.

It might seem weird but it's not, it's quite normal.
http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29

Re: How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

Well explained Jonathan
Thanks

On Tue, Aug 5, 2014 at 10:10 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
>> Yes I did that before, I removed the gcc and when I tried to build a
>> new gcc from source it crashed complaining that no C compiler is
>> present. Isn't it weird that installation of C compiler needs C
>> compiler as a pre-requisite.?
>
> You don't need a compiler to install a C compiler, you need a compiler
> to *compile* a C compiler, just like you need a compiler to compile
> any program.
>
> If you just want to install gcc you use 'yum' or 'rpm' to do that,
> instead of compiling it yourself.
>
> If you want to compile gcc, obviously you need a compiler of some kind.
>
> It might seem weird but it's not, it's quite normal.
> http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29



-- 
 Syed Ahsan Ali Bokhari
 Electronic Engineer
 Research & Development Division
 Pakistan Meteorological Department H-8/2, Islamabad.
 Phone # off +92519250361
 Cell # +923155145014
 Fax # +92519250368
 www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

I have set following paths in .bashrc to correspond to the latest
installation of gcc
export PATH=$PATH:/opt/gcc-4.9.1/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/gcc-4.9.1/lib:/opt/gcc-4.9.1/lib64

but still on run time the previous binaries/libraries are being found

[rcm@rcm ~]$ which gcc
/usr/bin/gcc

How to handle this?

On Wed, Aug 6, 2014 at 8:16 AM, Syed Ahsan Ali Bokhari
<ahsan.pmd@gmail.com> wrote:
> Well explained Jonathan
> Thanks
>
> On Tue, Aug 5, 2014 at 10:10 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>> On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
>>> Yes I did that before, I removed the gcc and when I tried to build a
>>> new gcc from source it crashed complaining that no C compiler is
>>> present. Isn't it weird that installation of C compiler needs C
>>> compiler as a pre-requisite.?
>>
>> You don't need a compiler to install a C compiler, you need a compiler
>> to *compile* a C compiler, just like you need a compiler to compile
>> any program.
>>
>> If you just want to install gcc you use 'yum' or 'rpm' to do that,
>> instead of compiling it yourself.
>>
>> If you want to compile gcc, obviously you need a compiler of some kind.
>>
>> It might seem weird but it's not, it's quite normal.
>> http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29
>
>
>
> --
>  Syed Ahsan Ali Bokhari
>  Electronic Engineer
>  Research & Development Division
>  Pakistan Meteorological Department H-8/2, Islamabad.
>  Phone # off +92519250361
>  Cell # +923155145014
>  Fax # +92519250368
>  www.pmd.gov.pk



-- 
 Syed Ahsan Ali Bokhari
 Electronic Engineer
 Research & Development Division
 Pakistan Meteorological Department H-8/2, Islamabad.
 Phone # off +92519250361
 Cell # +923155145014
 Fax # +92519250368
 www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Kyrill Tkachov]

On 06/08/14 11:11, Syed Ahsan Ali Bokhari wrote:
> I have set following paths in .bashrc to correspond to the latest
> installation of gcc
> export PATH=$PATH:/opt/gcc-4.9.1/bin
> export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/gcc-4.9.1/lib:/opt/gcc-4.9.1/lib64
>
> but still on run time the previous binaries/libraries are being found
>
> [rcm@rcm ~]$ which gcc
> /usr/bin/gcc
>
> How to handle this?

PATH is usually read left to right, so you'd want to add your new path 
to the beginning like so:

export PATH=/opt/gcc-4.9.1/bin:$PATH

Kyrill


> On Wed, Aug 6, 2014 at 8:16 AM, Syed Ahsan Ali Bokhari
> <ahsan.pmd@gmail.com> wrote:
>> Well explained Jonathan
>> Thanks
>>
>> On Tue, Aug 5, 2014 at 10:10 PM, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>>> On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
>>>> Yes I did that before, I removed the gcc and when I tried to build a
>>>> new gcc from source it crashed complaining that no C compiler is
>>>> present. Isn't it weird that installation of C compiler needs C
>>>> compiler as a pre-requisite.?
>>> You don't need a compiler to install a C compiler, you need a compiler
>>> to *compile* a C compiler, just like you need a compiler to compile
>>> any program.
>>>
>>> If you just want to install gcc you use 'yum' or 'rpm' to do that,
>>> instead of compiling it yourself.
>>>
>>> If you want to compile gcc, obviously you need a compiler of some kind.
>>>
>>> It might seem weird but it's not, it's quite normal.
>>> http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29
>>
>>
>> --
>>   Syed Ahsan Ali Bokhari
>>   Electronic Engineer
>>   Research & Development Division
>>   Pakistan Meteorological Department H-8/2, Islamabad.
>>   Phone # off +92519250361
>>   Cell # +923155145014
>>   Fax # +92519250368
>>   www.pmd.gov.pk
>
>

Re: How to uninstall pre-installed previous version and install new

[Syed Ahsan Ali Bokhari]

Thank you Kyrill. Now the new path is being read. Does the same hold
for LD_LIBRARY_PATH?

On Wed, Aug 6, 2014 at 3:23 PM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
>
> On 06/08/14 11:11, Syed Ahsan Ali Bokhari wrote:
>>
>> I have set following paths in .bashrc to correspond to the latest
>> installation of gcc
>> export PATH=$PATH:/opt/gcc-4.9.1/bin
>> export
>> LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/gcc-4.9.1/lib:/opt/gcc-4.9.1/lib64
>>
>> but still on run time the previous binaries/libraries are being found
>>
>> [rcm@rcm ~]$ which gcc
>> /usr/bin/gcc
>>
>> How to handle this?
>
>
> PATH is usually read left to right, so you'd want to add your new path to
> the beginning like so:
>
> export PATH=/opt/gcc-4.9.1/bin:$PATH
>
> Kyrill
>
>
>
>> On Wed, Aug 6, 2014 at 8:16 AM, Syed Ahsan Ali Bokhari
>> <ahsan.pmd@gmail.com> wrote:
>>>
>>> Well explained Jonathan
>>> Thanks
>>>
>>> On Tue, Aug 5, 2014 at 10:10 PM, Jonathan Wakely <jwakely.gcc@gmail.com>
>>> wrote:
>>>>
>>>> On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
>>>>>
>>>>> Yes I did that before, I removed the gcc and when I tried to build a
>>>>> new gcc from source it crashed complaining that no C compiler is
>>>>> present. Isn't it weird that installation of C compiler needs C
>>>>> compiler as a pre-requisite.?
>>>>
>>>> You don't need a compiler to install a C compiler, you need a compiler
>>>> to *compile* a C compiler, just like you need a compiler to compile
>>>> any program.
>>>>
>>>> If you just want to install gcc you use 'yum' or 'rpm' to do that,
>>>> instead of compiling it yourself.
>>>>
>>>> If you want to compile gcc, obviously you need a compiler of some kind.
>>>>
>>>> It might seem weird but it's not, it's quite normal.
>>>> http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29
>>>
>>>
>>>
>>> --
>>>   Syed Ahsan Ali Bokhari
>>>   Electronic Engineer
>>>   Research & Development Division
>>>   Pakistan Meteorological Department H-8/2, Islamabad.
>>>   Phone # off +92519250361
>>>   Cell # +923155145014
>>>   Fax # +92519250368
>>>   www.pmd.gov.pk
>>
>>
>>
>
>



-- 
 Syed Ahsan Ali Bokhari
 Electronic Engineer
 Research & Development Division
 Pakistan Meteorological Department H-8/2, Islamabad.
 Phone # off +92519250361
 Cell # +923155145014
 Fax # +92519250368
 www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Raghunath Lolur]

Yes, the same holds for LD_LIBRARY_PATH also.

In fact, a program/library will be searched in the order of sequence
of path specified from left to right in its corresponding environment
variable.


Regards,
Raghunath Lolur.

On Wed, Aug 6, 2014 at 6:21 PM, Syed Ahsan Ali Bokhari
<ahsan.pmd@gmail.com> wrote:
> Thank you Kyrill. Now the new path is being read. Does the same hold
> for LD_LIBRARY_PATH?
>
> On Wed, Aug 6, 2014 at 3:23 PM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
>>
>> On 06/08/14 11:11, Syed Ahsan Ali Bokhari wrote:
>>>
>>> I have set following paths in .bashrc to correspond to the latest
>>> installation of gcc
>>> export PATH=$PATH:/opt/gcc-4.9.1/bin
>>> export
>>> LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/opt/gcc-4.9.1/lib:/opt/gcc-4.9.1/lib64
>>>
>>> but still on run time the previous binaries/libraries are being found
>>>
>>> [rcm@rcm ~]$ which gcc
>>> /usr/bin/gcc
>>>
>>> How to handle this?
>>
>>
>> PATH is usually read left to right, so you'd want to add your new path to
>> the beginning like so:
>>
>> export PATH=/opt/gcc-4.9.1/bin:$PATH
>>
>> Kyrill
>>
>>
>>
>>> On Wed, Aug 6, 2014 at 8:16 AM, Syed Ahsan Ali Bokhari
>>> <ahsan.pmd@gmail.com> wrote:
>>>>
>>>> Well explained Jonathan
>>>> Thanks
>>>>
>>>> On Tue, Aug 5, 2014 at 10:10 PM, Jonathan Wakely <jwakely.gcc@gmail.com>
>>>> wrote:
>>>>>
>>>>> On 5 August 2014 17:54, Syed Ahsan Ali Bokhari wrote:
>>>>>>
>>>>>> Yes I did that before, I removed the gcc and when I tried to build a
>>>>>> new gcc from source it crashed complaining that no C compiler is
>>>>>> present. Isn't it weird that installation of C compiler needs C
>>>>>> compiler as a pre-requisite.?
>>>>>
>>>>> You don't need a compiler to install a C compiler, you need a compiler
>>>>> to *compile* a C compiler, just like you need a compiler to compile
>>>>> any program.
>>>>>
>>>>> If you just want to install gcc you use 'yum' or 'rpm' to do that,
>>>>> instead of compiling it yourself.
>>>>>
>>>>> If you want to compile gcc, obviously you need a compiler of some kind.
>>>>>
>>>>> It might seem weird but it's not, it's quite normal.
>>>>> http://en.wikipedia.org/wiki/Bootstrapping_%28compilers%29
>>>>
>>>>
>>>>
>>>> --
>>>>   Syed Ahsan Ali Bokhari
>>>>   Electronic Engineer
>>>>   Research & Development Division
>>>>   Pakistan Meteorological Department H-8/2, Islamabad.
>>>>   Phone # off +92519250361
>>>>   Cell # +923155145014
>>>>   Fax # +92519250368
>>>>   www.pmd.gov.pk
>>>
>>>
>>>
>>
>>
>
>
>
> --
>  Syed Ahsan Ali Bokhari
>  Electronic Engineer
>  Research & Development Division
>  Pakistan Meteorological Department H-8/2, Islamabad.
>  Phone # off +92519250361
>  Cell # +923155145014
>  Fax # +92519250368
>  www.pmd.gov.pk

Re: How to uninstall pre-installed previous version and install new

[Quanyang Liu]

On 08/06/14 00:54, Syed Ahsan Ali Bokhari wrote:
> Yes I did that before, I removed the gcc and when I tried to build a
> new gcc from source it crashed complaining that no C compiler is
> present. Isn't it weird that installation of C compiler needs C
> compiler as a pre-requisite.?
>
Why did you do that ... It's amazing.

-- 
Quanyang Liu （刘全阳）
Undergraduate
Department of Computer Science and Engineering
Shanghai Jiao Tong University
E-mail:lqymgt@gmail.com