The Linux system integrates various tools for calculating checksums,
md5sum. We can use these tools to calculate
the checksum of specified files, and compare the changes of the
checksums before and after modifying the file. Below commands use
md5sum to calculate the checksums of the
hello.c file before and
$ md5sum hello.c 87cb921a75d4211a57ba747275e8bbe6 //Original MD5 checksum of hello.c $ md5sum hello.c 79c3416910f9ea0d65a72cb720368416 //New MD5 checksum after adding one line
It can be seen that modifying just one line of code in the original file will result in greatly different MD5 checksums.