Friday, May 22, 2009

Interview Question

Yet another interview question that I came up with. This one tests the interviewee's ability to read and understand basic specifications.
You have a C program written to run on Linux that uses strndup(3), size-bounded string duplication. The function returns a copy of a source string only up to n characters. The copy is allocated using malloc(), and the copy is always zero-terminated even when the source string may not be. When you try to compile the program on Mac OS X, you found out that their Standard C library doesn't have strndup().
After browsing around, you found the functions strlcpy(3) and strlcat(3) which are the size-bounded string copying and concatenation. Can you use them along with malloc() to implement strndup()? If so, show your work. If not, explain why not.

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