[SOLVED] Capturing error message of curl in BASH script andchecking status

Issue

I need 4 things from curl in a BASH script:

• I need to capture brief humanly readable error message from curl into a bash variable.
• I need to be able to check that the command completed successfully or not.
• I need the command to run
• I don't want anything printed to console unless I echo it.

m=$(curl -u "$user":AP"$pass" -T "$pathA" "$url")
if [ $? -ne 0 ] ; then
   echo "Error: ""$m"
fi

The problem is curl puts gibberish into $m. It just dumps the error to console instead of m. I don't want anything printed to console unless I echo it. And I only want to capture error descriptions. I tried many variations, nothing seemed to work for this use-case... at least nothing suggested here on Stack.

Solution

curl sends errors to STDERR and will not get captured by $m. The output of curl is sent to STDERR (that gibberish you mentioned).

One solution is to redirect STDERR to STDOUT by adding 2>&1 to your curl invocation in your script:

m=$(curl -u "$user":AP"$pass" -T "$pathA" "$url" 2>&1)
if [ $? -ne 0 ] ; then
   echo "Error: ""$m"
fi

You could also use the --fail, --silent and --show-errors flags of curl like in this example if all you care about are the errors:

Making curl send errors to stderr and everything else to stdout

and some information about capturing STDERR to $variable in bash scripts:

Bash how do you capture stderr to a variable?

Answered By - oaccamsrazor

Answer Checked By - Robin (WPSolving Admin)