如何将字符串与 bash 中的可选字符匹配？

Question

I have a small little script that deals with pipelines on Jenkins. It needs to be able to grab a file from a folder named after the pipeline name.

Most pipeline names follow this pattern: {Name}Pipeline/{Name}Pipeline.properties

However, a few pipelines have a three-digit version number appended, like so: {Name}Pipeline122/{Name}Pipeline122.properties

In my script, I have a line that stores the path to this properties file in a variable: APP_PROPERTY_FILE=/path/to/file/${NAME}Pipeline/${NAME}Pipeline.properties

Herein lies the problem? How can I allow bash to match pipeline names without the version number AND pipeline names with the version number?

Thanks!

Answer 1

I believe that the user want to select a file that has optional element (3 digit number), and store the file name into shell variable.

Two challenges: (1) regular assignment var=/path/to/something* do not perform pathname expansion and (2) regular pattern matching do not support optional elements.

Possible solutions are 'if-then-else' or using extended globs. Both solutions assumed that one of the files exists.

APP_PROPERTY_FILE=/path/to/file/${NAME}Pipeline/${NAME}Pipeline.properties
if [ ! -f "$APP_PROPERY_FILE" ] ; then
APP_PROPERTY_FILE=$(echo /path/to/file/${NAME}Pipeline/${NAME}Pipeline[0-9][-0-9][0-9].properties)

Using extglob can also work.

APP_PROPERTY_FILE=$(shopt -s extglob ; echo /path/to/file/${NAME}Pipeline/${NAME}Pipeline?([0-9][-0-9][0-9]).properties ; echo $1)