Remove Error From Output Using Sed in Bash

bluethundr · 09-06-2018, 10:27 AM

I'm building a list of aws users with this command:

Code:

aws iam get-user --user-name "$aws_user_name" --profile="$aws_key"

If the user doesn't exist you get this output:

Code:

aws iam get-user --user-name fred --profile=lab 
    
    An error occurred (NoSuchEntity) when calling the GetUser operation: The user with name fred cannot be found.

I can suppress that error on the user output with this command, but a new error appears:

Code:

aws iam get-user --user-name fred --profile=lab 2>&1 | sed 's/^An error occurred (NoSuchEntity)\.*//g' |  jq -r '.User.UserName'
    parse error: Invalid numeric literal at line 2, column 6

I try to remove the parse error with the next line, but it doesn't work

Code:

aws iam get-user --user-name fred --profile=lab 2>&1 | sed 's/^An error occurred (NoSuchEntity)\.*//g' |  sed 's/parse\ error\.*//g' | jq -r '.User.UserName'
    parse error: Invalid numeric literal at line 2, column 6

How can I get rid of the parse error from the user output?

I'm writing the same line to a log file with the error intact for later analysis. But I don't want the user to see these errors.

rtmistler · 09-06-2018, 10:38 AM

I think you want to be more simple than global search-replace.

I wasn't totally sure, so looked up "sed delete line" https://stackoverflow.com/questions/...pecific-string

So you might do something more like:

Code:

sed 'An error occurred/d'

That should delete any lines containing that pattern.

individual · 09-06-2018, 10:59 AM

Try changing

Code:

jq -r '.User.UserName'

to

Code:

jq -r '.User?.UserName?'

.
By adding the question marks jq won't complain if either of those keys don't exist.

berndbausch · 09-06-2018, 11:38 PM

Quote:

Originally Posted by bluethundr

I'm building a list of aws users with this command:

Code:

aws iam get-user --user-name "$aws_user_name" --profile="$aws_key"

If the user doesn't exist you get this output:

Code:

aws iam get-user --user-name fred --profile=lab 
    
    An error occurred (NoSuchEntity) when calling the GetUser operation: The user with name fred cannot be found.

I can suppress that error on the user output with this command, but a new error appears:

Code:

aws iam get-user --user-name fred --profile=lab 2>&1 | sed 's/^An error occurred (NoSuchEntity)\.*//g' |  jq -r '.User.UserName'
    parse error: Invalid numeric literal at line 2, column 6

I try to remove the parse error with the next line, but it doesn't work

Code:

aws iam get-user --user-name fred --profile=lab 2>&1 | sed 's/^An error occurred (NoSuchEntity)\.*//g' |  sed 's/parse\ error\.*//g' | jq -r '.User.UserName'
    parse error: Invalid numeric literal at line 2, column 6

How can I get rid of the parse error from the user output?

I'm writing the same line to a log file with the error intact for later analysis. But I don't want the user to see these errors.

Is it an option to simply redirect all error output to some file for later analysis? E.g.

Code:

aws ... 2>/var/tmp/aws.err

If not, run the pipeline without the jq command and check line 2, column 6.

By the way, the \.* part of your sed string means “any number of dots” and is probably irrelevant.