grep files based on time stamp

Question

This should be pretty simple, but I am not figuring it out. I have a large code base more than 4GB under Linux. A few header files and xml files are generated during build (using gnu make). If it matters the header files are generated based on xml files.

I want to search for a keyword in header file that was last modified after a time instance ( Its my start compile time), and similarly xml files, but separate grep queries.

If I run it on all possible header or xml files, it take a lot of time. Only those that were auto generated. Further the search has to be recursive, since there are a lot of directories and sub-directories.

Answer 1

You could use the find command:

find . -mtime 0 -type f

prints a list of all files (-type f) in and below the current directory (.) that were modified in the last 24 hours (-mtime 0, 1 would be 48h, 2 would be 72h, ...). Try

grep "pattern" $(find . -mtime 0 -type f)

Answer 2

To find 'pattern' in all files newer than some_file in the current directory and its sub-directories recursively:

find -newer some_file -type f -exec grep 'pattern' {} +

You could specify the timestamp directly in date -d format and use other find tests e.g., -name, -mmin.

The file list could also be generate by your build system if find is too slow.

More specific tools such as ack, etags, GCCSense might be used instead of grep.