bash: replace word/s on screen with sed?

webking · 05-12-2016, 07:53 AM

Hi all,

I need some help with bash commands to replace text live on the screen please. For example, currrently if I type "wget ?" I get "-bash: wget: command not found." What I would like to do is replace some text produce there. I want to replace the word "command" or any words before it prints out.

Is this possible? please advise.

Thanks a ton!

pan64 · 05-12-2016, 08:05 AM

I do not understand it at all. Do you want to catch the text entered and alter it before displayed?

webking · 05-12-2016, 08:06 AM

Alter it before displayed please. Thanks.

pan64 · 05-12-2016, 08:08 AM

can you show some examples? What should be displayed during type? (pressing any keys?)

grail · 05-12-2016, 09:47 AM

I am a bit confused to ... you want to change the standard error messages displayed by bash??

webking · 05-12-2016, 12:31 PM

Sorry for the confusion. Here's what I need to accomplish. For example:

Currently:
$ wget ? <ENTER>
-bash: wget: command not found

I want to see something like this after I hit the ENTER key.

$ wget ? <ENTER>
-bash: wget: WHATEVER not found

Basically after I hit enter, I want to hide or replace whatever text I wish in place of the original message. Please let me know if I m not clear again. Sorry.

webking · 05-12-2016, 12:40 PM

Quote:

Originally Posted by grail

you want to change the standard error messages displayed by bash??

Yes and add some extra. :O). Maybe I do not like the way it worded so I want a chance to replace some text. Thanks.

michaelk · 05-12-2016, 01:01 PM

By creating a shell function you can modify error messages a bit.

http://www.linuxjournal.com/magazine...proof?page=0,0
http://www.linuxplanet.com/linuxplan...orials/7025/1/

keefaz · 05-12-2016, 03:46 PM

With Bash version 4, it seems you can write your own command not found handler function

Code:

command_not_found_handle () {
  echo "What is this thing?" >&2
  return 127
}

$ notfoundcommand
What is this thing?

Edit:

Quote:

Originally Posted by webking

I want to see something like this after I hit the ENTER key.

$ wget ? <ENTER>
-bash: wget: WHATEVER not found

then the error message would be:

Code:

echo "-$0: $1: WHATEVER not found" >&2

Edit2:
I tend to like the trap handler method better (more possibilities), from the links given by michaelk