Equivs2 is software that can partition a set of files into equivalence classes in a relatively efficient manner, depending on the input size and options selected.
I recently came across equivs2, a software tool that can divide a series of files into equivalence classes. This tool has been designed and is suitable for use with a very large number of files and/or very large files. One of the most impressive features of equivs2 is that it can perform its task strictly in terms of cryptographic digests. It can use cryptographic digests backed up at the end with full byte-for-byte comparisons.
Equivs2 also uses some heuristics like comparing the beginnings of files and the device number and inode number and file sizes. Another impressive feature of the tool is that it knows only to read in the parts that it needs "so far," thus avoiding a huge inhale at the beginning of the run. Instead, it tries an initial method and falls back to subsequent methods as needed.
When using equivs2, you can use the following options:
- The -v option lets you operate the tool verbosely.
- The -s option lets you get filenames from stdin instead of from the command line.
- The -0 option says that when getting filenames from stdin, assume null termination, not newline termination.
- The -h option gives you a message detailing the tool's usage.
- The -f option lets you use the listed files, not files from stdin.
- The -p option lets you cache a certain number of bytes of each file for faster comparisons (may be 0).
- The -d option lets you change the default output delimiter to a null byte, because some shells cannot handle that.
- The -c option lets you not do full comparisons-instead, trust hash comparisons. This option makes the tool faster at the expense of some accuracy.
Overall, equivs2 is a powerful tool that you can use to divide files into equivalence classes. It has many useful features and options that you can use depending on your requirements.
Equivs2 also uses some heuristics like comparing the beginnings of files and the device number and inode number and file sizes. Another impressive feature of the tool is that it knows only to read in the parts that it needs "so far," thus avoiding a huge inhale at the beginning of the run. Instead, it tries an initial method and falls back to subsequent methods as needed.
When using equivs2, you can use the following options:
- The -v option lets you operate the tool verbosely.
- The -s option lets you get filenames from stdin instead of from the command line.
- The -0 option says that when getting filenames from stdin, assume null termination, not newline termination.
- The -h option gives you a message detailing the tool's usage.
- The -f option lets you use the listed files, not files from stdin.
- The -p option lets you cache a certain number of bytes of each file for faster comparisons (may be 0).
- The -d option lets you change the default output delimiter to a null byte, because some shells cannot handle that.
- The -c option lets you not do full comparisons-instead, trust hash comparisons. This option makes the tool faster at the expense of some accuracy.
Overall, equivs2 is a powerful tool that you can use to divide files into equivalence classes. It has many useful features and options that you can use depending on your requirements.
What's New
Version 3.0: N/A