Instructions for execution
---------------------------
make clean
make all
./write_backup ls -l -t -r
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This ptrace based extension creates backups for files before they are being written. It creates backups for cases like opening a file for write access, renaming a file, truncating a file, writing to a file. The backups are stored with timestamp to maintain versioning in '/home/sekar/bk'. If bk folder doesnt exist, the program creates the folder and then writes to it. Extensions of files are also preserved. 

There is also a test file test.c used for testing the above scenarios and can be used like:

./write_backup ./test_ans

References
https://www.linuxjournal.com/article/6100
stackoverflow.com