12.71.4 memmem

Gnulib module: memmem or memmem-simple

Both modules implement the same replacement for the memmem function with the memmem module providing a replacement on more platforms where the existing memmem function has a quadratic worst-case complexity.

Portability problems fixed by either Gnulib module memmem-simple or memmem:

• This function is missing on some platforms: Mac OS X 10.5, FreeBSD 5.2.1, OpenBSD 4.0, Minix 3.1.8, AIX 4.3.2, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, mingw, MSVC 9, Interix 3.5, BeOS.
• This function has reversed arguments on some older platforms: Linux libc 5.0.9
• This function can trigger false positives for long periodic needles on some platforms: glibc 2.12, Cygwin 1.7.7.
• This function returns incorrect values in some cases, such as when given an empty needle: glibc <= 2.0, Solaris 11 2011-11, Cygwin 1.5.x.

Performance problems fixed by Gnulib module memmem:

• This function has quadratic instead of linear worst-case complexity on some platforms: glibc 2.8, FreeBSD 6.2, NetBSD 5.0, AIX 5.1, Solaris 11 2011-11, Cygwin 1.5.x. Note for small needles the replacement may be slower.

Portability problems not fixed by Gnulib: