BSD string and memory functions

String interfaces specified by American National Standards Institute/International Standards Organization (ANSI/ISO) C are in <string.h>. String interfaces only in the Single UNIX Specification are in <strings.h>. The <strings.h> file contains:

• bcmp()
• bcopy()
• bzero()
• ffs()
• index()
• rindex()
• strcasecmp()
• strdup()
• strncasecmp()

The Interix Software Development Kit (SDK) also supports the Berkeley Software Distribution (BSD) 4.4 strsep() and strcasestri() routines.