[TUHS] Warner's Early Unix Presentation

Chet Ramey chet.ramey at case.edu
Sun Feb 9 09:26:51 AEST 2020

On 2/8/20 6:11 PM, Rob Pike wrote:
> Not for me it doesn't.
> % bash
> bash-3.2$ function f() {
>     echo hi
>     }
> bash-3.2$ export f 
> bash-3.2$ bash 
> bash-3.2$ f 
> bash-3.2$ 

jenna(1)$ echo $BASH_VERSION
jenna(1)$ f() { echo f; }
jenna(1)$ export -f f
jenna(1)$ bash
jenna(2)$ f

It works the same in Mac OS X's bash-3.2.

> I added the 'builtin' command, which did leave the labs. But I added it as
> a way for the "whatis" command to show a builtin, as well as allowing a way
> to guarantee you get the builtin on execution.

Bash uses `type' to tell whether something is a builtin. How does `builtin'
say whether or not a command is builtin? The output with no arguments?

> How do I get bash to print the function as (shell) source code, so I could
> edit it and play with it again? It was the synergy of all this stuff
> connected seamlessly that made it so compelling.

jenna(2)$ declare -pf f
f ()
    echo f
declare -fx f

If it weren't exported, you wouldn't get the `declare' command appended

``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet at case.edu    http://tiswww.cwru.edu/~chet/

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