redirect bash output and error for all commands

Question

How to redirect all commands executed on the bash to /dev/null ?

It's obvious that for a command we have to do:

command > /dev/null  2>&1

How about all commands that will be executed further on ?

hek2mgl · Answer 1 · 2013-05-22T15:55:59.657

5

Simply start a new shell:

bash >/dev/null 2>&1

Now you can type commands blind :) If you want to leave that mode type: exit

But typing commands blind will normally not what you want. So I would suggest to create a text file like script.sh, place your commands in it:

command1 foo 
command2 bar

and than execute it using:

bash script.sh >/dev/null 2>&1

The ouput of all commands in that script will be redirected to /dev/null now

edited May 22 '13 at 15:55

answered May 22 '13 at 15:44

hek2mgl

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I got this: [1] 13407 bash: 2: No such file or directory 1: command not found [1]+ Exit 127 bash 2 > /dev/null – TheForbidden May 22 '13 at 15:54
try `/usr/bin/bash` instead of `bash`. Btw, which system are you using? – hek2mgl May 22 '13 at 15:57
yeah I do have it, but he doesn't recognize the 2 and the 1 – TheForbidden May 22 '13 at 16:18
Type it by your own hands no paste and copy – hek2mgl May 22 '13 at 16:19
yes it worked. But if I want to redirect only the error output ? – TheForbidden May 22 '13 at 16:22

score 3 · Answer 2 · answered May 22 '13 at 15:48

3

Use exec without a command:

exec > /dev/null 2>&1

As hex2mgl pointed out, if you do this in an interactive shell, you won't even see your prompt anymore, as the shell prints that to standard error. I assume this is intended for a script, as it doesn't make a lot of sense to ignore all output from commands run interactively :)

answered May 22 '13 at 15:48

chepner

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It's not blocked; all output (both standard output and standard error, which includes your prompt) has been redirected to `/dev/null`, as requested. – chepner May 22 '13 at 16:12
`exec 2>/dev/null`. But that will still redirect your typing and the prompt to `/dev/null`/. – chepner May 22 '13 at 16:21

score 0 · Answer 3 · answered May 22 '13 at 15:47

for scripting or other practical purpose, grouping the command is a nice solution. check http://www.gnu.org/software/bash/manual/html_node/Compound-Commands.html It says specifically Any redirections (see Redirections) associated with a compound command apply to all commands within that compound command unless explicitly overridden.

redirect bash output and error for all commands

3 Answers3