I'm working with RJDBC on a server whose maintainers frequently update jar versions. Since RJDBC requires classpaths, this poses a problem when paths break. My situation is fortuitous in that the most current jars will always be in the same directory, but the version numbers will have changed.
I'm trying to use a simple grep function in R to isolate which jar I need based on a regex with some AND logic, however R makes this surprisingly difficult...
This question demonstrates how grep in R can function with the | operator for OR logic, but I can't seem to find similar AND logic operator.
Here's an example:
## Let's say I have three jars in a directory
jars <- list.files('/the/dir')
> jars
[1] "hive-jdbc-1.1.0-cdh5.4.3-standalone.jar" "hive-jdbc-1.1.0-cdh5.4.3.jar" "jython-standalone-2.5.3.jar"
The jar I want is "hive-jdbc-1.1.0-cdh5.4.3-standalone.jar"—how can I use AND logic in grep to extract it?
## I know that OR logic is supported:
j <- jars[grep('hive-jdbc|standalone', jars)]
> j
[1] "hive-jdbc-1.1.0-cdh5.4.3-standalone.jar" "hive-jdbc-1.1.0-cdh5.4.3.jar" "jython-standalone-2.5.3.jar"
## Would AND logic look like the same format?
> jars[grep('hive-jdbc&standalone', jars)]
character(0)
Not all-that-surprisingly, that last piece doesn't work... I found a useful, yet non-comprehensive, link for grep in R, but it doesn't show an AND operator. Any thoughts?
