Rubin Shrestha
Rubin Shrestha
Blog

Bash script is getting a non successful result just after a loop reading lines from stdin

by |Published

I am experiencing, in my opinion, a not expected behavior when reading lines from stdin in a loop inside a bash script.

The section of the script which has that behavior looks like:


........

echo "$PROP_VALUE" | tr ':' 'n' | while read FILE_MAPPING
do
    errLog "entering to process FILE_MAPPING='$FILE_MAPPING'"
    BASE_FILE_TO_MAP="$( echo "$FILE_MAPPING" | awk -F'=' '{ print $1 }' )"

    IS_COMPOUND_FILENAME="$( echo "$BASE_FILE_TO_MAP" | grep "/" | wc -l )"

    MODEL_FILE_TO_COPY="$( echo "$FILE_MAPPING" | awk -F'=' '{ print $2 }' )"

    (( IS_COMPOUND_FILENAME > 0 )) && { errLog "'$BASE_FILE_TO_MAP' does not seem to be a basename, at '$MACHINE_PARTICULAR_INPUT_PROP_FILENAME', for label:'$MAPPING_LABELNAME'"; exit 11; }

    find "$DIRECTORIO_CONFIGURACION_GENERADA" -name "$BASE_FILE_TO_MAP" | while read FILE_TO_BE_REPLACED
    do
        FILE_TO_REPLACE_TO="$( get_paths_relative_to.py "$MACHINE_PARTICULAR_INPUT_PROP_FILENAME" "$MODEL_FILE_TO_COPY" )"
        errLog "   replacing '$FILE_TO_BE_REPLACED'  from: '$FILE_TO_REPLACE_TO'"
        cp -a "$FILE_TO_REPLACE_TO" "$FILE_TO_BE_REPLACED" || { errLog "Error when copying '$FILE_TO_REPLACE_TO' to '$FILE_TO_BE_REPLACED'"; exit 3; }
    done
    MY_RESULT=$?
    errLog "$? [1] = $MY_RESULT"
    (( MY_RESULT != 0 )) && exit 4
done

MY_RESULT=$?
errLog "$? [2] = $MY_RESULT"


exit $MY_RESULT

The value for PROP_VALUE is an equivalent one to: “xmlTransformation.xml=../../../../20260715.latestRules/TransformationRulesXml_GE.xml”

In a nutshell, the script aims to replace some files in a configuration instance, replacing them by the latest versions of those files depending on a configuration value.

And the output for the unexpected result execution is:

...
   replacing './XXXXXXXXXXXXXXXXXX/de/xmlTransformation.xml'  from: './ZZZZZZZZZZZZZZZZZZZZZZ/../../../../20260715.latestRules/TransformationRulesXml_GE.xml'
$? [1] = 0
$? [2] = 1

and the script returns a non-successful result to its caller.

I have not the experience to be sure that it is not the expected behavior, but it seems logical to get a result of 0 (success), and in my one liner checks emulating the look and even the double loop, the result I get is zero.

Do you know if the is any way to detect a failure inside the external loop at root level? Is there any way to detect a success of the external loop at root level?

You may also like