I have a lambda that I want to invoke using CLI. The LogResult in the output is base64 encoded data. I am trying to fetch the log data in "LogResult", remove the preceding and following double quotes, and eventually decode it. I am currently doing it using separate commands
$ aws lambda invoke --function-name test-lambda-function out --log-type Tail --query "LogResult" > output.log
$ sed -i 's/\"//g' output.log
$ base64 --decode output.log
But this seems needlessly verbose. I've been trying to pipe these commands but something is obviously wrong. I've tried the following
$ aws lambda invoke --function-name test-lambda-function out --log-type Tail --query "LogResult" | sed -i 's/\"//g' | base64 --decode
sed: unknown option -- decode
$ aws lambda invoke --function-name test-lambda-function out --log-type Tail --query "LogResult" | tr -d '"' | base64 --decode
tr: extra operand '|'
What's the neatest way to achieve what I want to do?
The cleanest way to combine these commands is by using command substitution and piping. The main issue in your attempts is mixing up the sed and tr commands with | pipes in the wrong context.
Here’s a one-liner that should do exactly what you want:
aws lambda invoke --function-name test-lambda-function out --log-type Tail --query "LogResult" --output text | tr -d '"' | base64 --decode
Here’s how it works:
aws lambda invoke ... --output text returns the output as plain text without the surrounding quotes.
tr -d '"' removes any remaining double quotes if necessary.
base64 --decode decodes the Base64 string to show the actual log content.
Explanation of the issues:
Using --output text with the AWS CLI removes the surrounding quotes automatically, so you don't need sed in this pipeline.
The | pipe is used correctly here to pass the result of each command to the next in sequence, without attempting to edit files directly.