Next: Trivial Encryption, Previous: Erasing Sensitive Data, Up: String and Array Utilities [Contents][Index]
The function below addresses the perennial programming quandary: “How do
I take good data in string form and painlessly turn it into garbage?”
This is actually a fairly simple task for C programmers who do not use
the GNU C Library string functions, but for programs based on the GNU C Library,
the strfry function is the preferred method for
destroying string data.
The prototype for this function is in string.h.
Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.
strfry creates a pseudorandom anagram of a string, replacing the
input with the anagram in place. For each position in the string,
strfry swaps it with a position in the string selected at random
(from a uniform distribution). The two positions may be the same.
The return value of strfry is always string.
Portability Note: This function is unique to the GNU C Library.