[Discuss] What the use of .bashrc

[John Abreau]

Oops, should have tested first.  $1 should have been $2.


On Tue, Oct 30, 2012 at 11:29 AM, John Abreau <abreauj at gmail.com> wrote:
> Interesting. I had written my own, ages ago, but I made them two
> separate functions. Also, they work not only for PATH, but for
> any similar environment variable such as MANPATH, CLASSPATH, etc.
>
> I never made them check for a pre-existing instance, though; they were
> simple one-liners. Thanks for the tip; I'm updating them to do that.
>
> Usage:
>
>     prepend-path PATH /path/to/bin
>     append-path PATH /path/to/bin
>
> prepend-path() {
>         case "$1" in
>         *:"$1":*)
>                 ;;
>         *)
>                 eval "$1=$2:\$$1" ;;
>         esac
> }
>
> append-path() {
>         case "$1" in
>         *:"$1":*)
>                 ;;
>         *)
>                 eval "$1=\$$1:$2" ;;
>         esac
> }
>
>
> On Tue, Oct 30, 2012 at 10:36 AM, Jerry Feldman <gaf at blu.org> wrote:
>> On 10/30/2012 10:13 AM, Rich Pieri wrote:
>>> On Tue, 30 Oct 2012 07:50:48 -0400
>>> Glenn Hoffman <glennhoffman at mac.com> wrote:
>>>> existence of .bashrc, since I have never used it myself. What's the
>>>> reason for a separate startup file for a non-login interactive shell?
>>> As a matter of principle, an interactive session should have one and
>>> only one login process associated with it. That's the login shell,
>>> whether it's BASH or something else.
>>>
>>> As a matter of practice, logging in on the console is a little
>>> different from starting a screen session. Having separate login and
>>> non-login run command files makes this easy keep sane. This is just one
>>> practical example among many.
>>>
>> Agreed. In the case of a Gnome or KDE session, it is the session that is
>> effectively the login shell. but neither gnome nor kde parse ~/.profile.
>> They generally use xinitrc.
>> The bottom line is it is, IMHO, best to set your path, environment
>> variables and  aliases ~/.bashrc. There is a very nice function in
>> /etc/bashrccalled pathmung() that allows you to add path variables to
>> your path either at the beginning or end but without duplicating anything:
>> pathmunge () {
>>     case ":${PATH}:" in
>>         *:"$1":*)
>>             ;;
>>         *)
>>             if [ "$2" = "after" ] ; then
>>                 PATH=$PATH:$1
>>             else
>>                 PATH=$1:$PATH
>>             fi
>>     esac
>> }
>>
>> If you read the function, it first tests to make sure your element is
>> not already in $PATH. In the default case '*)' it looks if you have
>> specified, 'after', and if so, it appends the element to your path,
>> otherwise it prepends.
>>
>>
>>
>> --
>> Jerry Feldman <gaf at blu.org>
>> Boston Linux and Unix
>> PGP key id:3BC1EB90
>> PGP Key fingerprint: 49E2 C52A FC5A A31F 8D66  C0AF 7CEA 30FC 3BC1 EB90
>>
>>
>>
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>>
>
>
>
> --
> John Abreau / Executive Director, Boston Linux & Unix
> PGP KeyID: 32A492D8 / Email: abreauj at gmail.com
> PGP FP: 7834 AEC2 EFA3 565C A4B6  9BA4 0ACB AD85 32A4 92D8



-- 
John Abreau / Executive Director, Boston Linux & Unix
PGP KeyID: 32A492D8 / Email: abreauj at gmail.com
PGP FP: 7834 AEC2 EFA3 565C A4B6  9BA4 0ACB AD85 32A4 92D8