STRING.H(7) Miscellaneous Information Manual STRING.H(7)

NAME

string.h — string operations

SYNOPSIS

#include <string.h>

DESCRIPTION

[CX] Some of the functionality described on this reference page extends the ISO C standard. Applications shall define the appropriate feature test macro (see the System Interfaces volume of IEEE Std 1003.1-2001 (“POSIX.1”), xsh_chap02_02(3)) to enable the visibility of these symbols in this header.

The <string.h> header shall define the following:

NULL: Null pointer constant.
size_t: As described in <stddef.h> .

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

[XSI]
void    *memccpy(void *restrict, const void *restrict, int, size_t);

void    *memchr(const void *, int, size_t);
int      memcmp(const void *, const void *, size_t);
void    *memcpy(void *restrict, const void *restrict, size_t);
void    *memmove(void *, const void *, size_t);
void    *memset(void *, int, size_t);
char    *strcat(char *restrict, const char *restrict);
char    *strchr(const char *, int);
int      strcmp(const char *, const char *);
int      strcoll(const char *, const char *);
char    *strcpy(char *restrict, const char *restrict);
size_t   strcspn(const char *, const char *);
[XSI]
char    *strdup(const char *);

char    *strerror(int);
[TSF]
int     *strerror_r(int, char *, size_t);

size_t   strlen(const char *);
char    *strncat(char *restrict, const char *restrict, size_t);
int      strncmp(const char *, const char *, size_t);
char    *strncpy(char *restrict, const char *restrict, size_t);
char    *strpbrk(const char *, const char *);
char    *strrchr(const char *, int);
size_t   strspn(const char *, const char *);
char    *strstr(const char *, const char *);
char    *strtok(char *restrict, const char *restrict);
[TSF]
char    *strtok_r(char *, const char *, char **);

size_t   strxfrm(char *restrict, const char *restrict, size_t);

[XSI] Inclusion of the <string.h> header may also make visible all symbols from <stddef.h>.

The following sections are informative.