Section: Linux Programmer's Manual (3)
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memmem - locate a substring
void *memmem(const void *haystack, size_t haystacklen,
const void *needle, size_t needlelen);
The memmem() function finds the start of the first occurrence
of the substring needle of length needlelen in the memory
area haystack of length haystacklen.
The memmem() function returns a pointer to the beginning of the
substring, or NULL if the substring is not found.
This function is a GNU extension.
This function was broken in Linux libraries up to and including libc 5.0.9;
there the `needle' and `haystack' arguments were interchanged,
and a pointer to the end of the first occurrence of needle
was returned. Since libc 5.0.9 is still widely used, this is a
dangerous function to use.
Both old and new libc's have the bug that if needle is empty
haystack-1 (instead of haystack) is returned.
And glibc 2.0 makes it worse, and returns a pointer to the
last byte of `haystack'. This is fixed in glibc 2.1.
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
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