singledelta - heuristic minimizer of interesting files
singledelta -test=test-script [options] [initial-file]
Delta assists you in minimizing "interesting" files subject to a test of their interestingness. A common such situation is when attempting to isolate a small failure-inducing substring of a large input that causes your program to exhibit a bug.
You supply singledelta with
- a test shell script which decides if its input file is "interesting" (test-script) and
- an initial interesting input file (initial-file or standard input).
Delta uses heuristics to find a sub-file of your input file that is still "interesting" according to your test.
Delta has a notion of the granularity of the file: the smallest atomic elements of which the file is seen as a sequence. The default is the line granularity: in this mode, delta will attempt to delete entire lines, but will never try deleting a smaller element than that. You can filter a program through topformflat(1) to produce a file where the line-granularity only goes to a specified nesting depth (if your file is in a nested language). multidelta(1) does this for you.
- Use test-script as the test program. This option is mandatory.
The test program accepts a single argument, the name of the candidate file to test. It is run within a directory containing only that file, and it can make temporary files/directories in that directory. It should return zero for a candidate that exhibits the desired property, and nonzero for one that does not.
- Set filename suffix to suffix. The default is ".c".
- Dump the contents of the initial file after reading it.
- Copy the minimal successful test to file.
- Use lines as the granularity. This is the default.
- Use C top-level forms as the granularity. This currently only works with CIL output.
- Log main events to file.
- Do not produce any output.
- Produce more verbose output.
- Overwrite initial-file with inputs.
- Print out usage information.
The name singledelta is Debian-specific. The upstream name of this program is simply delta.
Delta Debugging project <http://www.st.cs.uni-sb.de/dd/>