Is there a version of strstr that works over a fixed length of memory that may include null characters?
I could phrase my question like this: strncpy is to memcpy as strstr is to ?
+5
A:
memmem, unfortunately it's GNU-specific rather than standard C. However, it's open-source so you can copy the code (if the license is amenable to you).
Roger Pate
2010-01-02 18:03:21
+4
A:
Not in the standard library (which is not that large, so take a look). However writing your own is trivial, either directly byte by byte or using memchr() followed by memcmp() iteratively.
Clifford
2010-01-02 18:05:05
+1, I like the idea to use memchr and memcpy. You can take a strstr implementation verbatim and replace all the str-functions with their mem-counterparts.
quinmars
2010-01-02 21:55:17
A:
In the standard library, no. However, a quick google search for "safe c string library" turns up several potentially useful results. Without knowing more about the task you are trying to perform, I cannot recommend any particular third-party implementation.
If this is the only "safe" function that you need beyond the standard functions, then it may be best to roll your own rather than expend the effort of integrating a third-party library, provided you are confident that you can do so without introducing additional bugs.
Adam
2010-01-02 18:09:18
You are correct that I took a slightly different interpretation of the question. A broad reading of "may include nulls" could lead on to believe that it also may not include nulls. As lack of null termination is a major issue that leads people to consider `strncpy()` (and, indeed, `strlcpy()`), it seemed appropriate to address my answer from that direction, since other answers had already covered other approaches. I attempted to note this by stating "Without knowing more about the task ... I cannot recommend any particular third-party implementation." Perhaps I could have been more clear.
Adam
2010-01-02 18:36:28