Read a file, extract contents encapsulated in parentheses

Sourced from http://objectmix.com/awk/26995-retrieve-string-between-parentheses.html

$ cat some_file | gawk '{if (match($0,/\((.*)\)/,f)) print f[1]}' | cut -d ':' -f1 | sort | uniq

The above command will be helpful when reviewing stack trace output from command line to filter out and identify all the referenced .java files listed.

For example:

$ cat stacktrace_1.txt | gawk '{if (match($0,/\((.*)\)/,f)) print f[1]}' | cut -d ':' -f1 | sort | uniq
FilterFileSystem.java
Job.java
JobSubmissionFiles.java
JobSubmitter.java
Native Method
ProcessBuilder.java
RawLocalFileSystem.java
Shell.java
Subject.java
ToolRunner.java
UserGroupInformation.java