Allow --sum-report to take filenames from a file

[ericfrederich]

I generate reports and store them inside of each Git repo under .git/reports/cloc.
For a small amount of reports I'm able to do the following.

cloc --sum-report $(find ~/src -path "*/.git/reports/cloc")

But Linux/Bash has its limitations and with thousands of projects this doesn't work.

Suggestion

Add a new option --sum-report-file. Then I should be able to get a summary by doing the following:

find ~/src -path "*/.git/reports/cloc" > /tmp/all_reports
cloc --sum-report-file /tmp/all_reports

[AlDanial]

Oddly enough, cloc can already do this. The trick is to use the --vcs switch. Although --vcs was designed to support versioning tools like git, svn, etc, it will work with any command that returns a list of files. Therefore you just need to do

cloc --vcs="cat /tmp/all_reports" --sum-reports

[AlDanial]

--vcs was not an obvious solution; to help others find this capability I added --files-from as a synonym to it.