Hello
I have seen some code with #include<string.h> and some code with
#include<strings.h>.
However one is a symlink to the other.
My question is: what is the distinction between these headers?
string.h is a C standard library header. It's supposed to contain
declarations or definitions of the following items (Appendix B.23):
=====================================================================
size_t
NULL
void *memcpy(void * restrict s1,
const void * restrict s2, size_t n);
void *memmove(void *s1, const void *s2, size_t n);
char *strcpy(char * restrict s1,
const char * restrict s2);
char *strncpy(char * restrict s1,
const char * restrict s2, size_t n);
char *strcat(char * restrict s1,
const char * restrict s2);
char *strncat(char * restrict s1,
const char * restrict s2, size_t n);
int memcmp(const void *s1, const void *s2, size_t n);
int strcmp(const char *s1, const char *s2);
int strcoll(const char *s1, const char *s2);
int strncmp(const char *s1, const char *s2, size_t n);
size_t strxfrm(char * restrict s1,
const char * restrict s2, size_t n);
void *memchr(const void *s, int c, size_t n);
char *strchr(const char *s, int c);
size_t strcspn(const char *s1, const char *s2);
char *strpbrk(const char *s1, const char *s2);
char *strrchr(const char *s, int c);
size_t strspn(const char *s1, const char *s2);
char *strstr(const char *s1, const char *s2);
char *strtok(char * restrict s1,
const char * restrict s2);
void *memset(void *s, int c, size_t n);
char *strerror(int errnum);
size_t strlen(const char *s);
_ _STDC_WANT_LIB_EXT1_ _
errno_t
rsize_t
errno_t memcpy_s(void * restrict s1, rsize_t s1max,
const void * restrict s2, rsize_t n);
errno_t memmove_s(void *s1, rsize_t s1max,
const void *s2, rsize_t n);
errno_t strcpy_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2);
errno_t strncpy_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
rsize_t n);
errno_t strcat_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2);
errno_t strncat_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
rsize_t n);
char *strtok_s(char * restrict s1,
rsize_tsize_t strxfrm(char * restrict s1,
const char * restrict s2, size_t n);
void *memchr(const void *s, int c, size_t n);
char *strchr(const char *s, int c);
size_t strcspn(const char *s1, const char *s2);
char *strpbrk(const char *s1, const char *s2);
char *strrchr(const char *s, int c);
size_t strspn(const char *s1, const char *s2);
char *strstr(const char *s1, const char *s2);
char *strtok(char * restrict s1,
const char * restrict s2);
void *memset(void *s, int c, size_t n);
char *strerror(int errnum);
size_t strlen(const char *s);
_ _STDC_WANT_LIB_EXT1_ _
errno_t
rsize_t
errno_t memcpy_s(void * restrict s1, rsize_t s1max,
const void * restrict s2, rsize_t n);
errno_t memmove_s(void *s1, rsize_t s1max,
const void *s2, rsize_t n);
errno_t strcpy_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2);
errno_t strncpy_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
rsize_t n);
errno_t strcat_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2);
errno_t strncat_s(char * restrict s1,
rsize_t s1max,
const char * restrict s2,
rsize_t n);
char *strtok_s(char * restrict s1,
rsize_t * restrict s1max,
const char * restrict s2,
char ** restrict ptr);
errno_t memset_s(void *s, rsize_t smax, int c, rsize_t n)
errno_t strerror_s(char *s, rsize_t maxsize,
errno_t errnum);
size_t strerrorlen_s(errno_t errnum);
size_t strnlen_s(const char *s, size_t maxsize);
strings.h is not a C standard library header. It could be many different
things. If you're using a unix-like systems, one thing it could be is an
X/Open System Interfaces (XSI) extension. That header is supposed to
contain the following declarations
<
http://pubs.opengroup.org/onlinepubs/009695399/toc.htm>:
==========================================================
int bcmp(const void *, const void *, size_t); (LEGACY )
void bcopy(const void *, void *, size_t); (LEGACY )
void bzero(void *, size_t); (LEGACY )
int ffs(int);
char *index(const char *, int); (LEGACY )
char *rindex(const char *, int); (LEGACY )
int strcasecmp(const char *, const char *);
int strncasecmp(const char *, const char *, size_t);
There's not a single item in common between those two files, other than
the fact that they both need a typedef for size_t. Creating a single
file to serve both purposes seems quite odd. What you've got might be
something else entirely. How well do the contents match those two lists?
