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 XSH 2.2 The Compilation Environment ) to enable the visibility of these symbols in this header.

The <string.h> header shall define NULL and size_t as described in <stddef.h>.

^[CX] The <string.h> header shall define the locale_t type as described in <locale.h>.

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided for use with ISO C standard compilers.

[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);
[CX]
void    *memmem(const void *, size_t, const void *, size_t);

void    *memmove(void *, const void *, size_t);
void    *memset(void *, int, size_t);
[CX]
char    *stpcpy(char *restrict, const char *restrict);
char    *stpncpy(char *restrict, const char *restrict, 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 *);
[CX]
int      strcoll_l(const char *, const char *, locale_t);

char    *strcpy(char *restrict, const char *restrict);
size_t   strcspn(const char *, const char *);
[CX]
char    *strdup(const char *);

char    *strerror(int);
[CX]
char    *strerror_l(int, locale_t);
int      strerror_r(int, char *, size_t);
size_t   strlcat(char *restrict, const char *restrict, size_t);
size_t   strlcpy(char *restrict, const char *restrict, 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);
[CX]
char    *strndup(const char *, size_t);
size_t   strnlen(const char *, size_t);

char    *strpbrk(const char *, const char *);
char    *strrchr(const char *, int);
[CX]
char    *strsignal(int);

size_t   strspn(const char *, const char *);
char    *strstr(const char *, const char *);
char    *strtok(char *restrict, const char *restrict);
[CX]
char    *strtok_r(char *restrict, const char *restrict, char **restrict);

size_t   strxfrm(char *restrict, const char *restrict, size_t);
[CX]
size_t   strxfrm_l(char *restrict, const char *restrict,
             size_t, locale_t);

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

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

<locale.h> , <stddef.h> , <sys/types.h>

XSH 2.2 The Compilation Environment , memccpy , memchr , memcmp , memcpy , memmem , memmove , memset , strcat , strchr , strcmp , strcoll , strcpy , strcspn , strdup , strerror , strlcat , strlen , strncat , strncmp , strncpy , strpbrk , strrchr , strsignal , strspn , strstr , strtok , strxfrm

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 5

The DESCRIPTION is updated for alignment with the POSIX Threads Extension.

Issue 6

The strtok_r() function is marked as part of the Thread-Safe Functions option.

This reference page is updated to align with the ISO/IEC 9899:1999 standard.

The strerror_r() function is added in response to IEEE PASC Interpretation 1003.1c #39.

Issue 7

SD5-XBD-ERN-15 is applied, correcting the prototype for the strerror_r() function.

The stpcpy(), stpncpy(), strndup(), strnlen(), and strsignal() functions are added from The Open Group Technical Standard, 2006, Extended API Set Part 1.

The strcoll_l(), strerror_l(), and strxfrm_l() functions are added from The Open Group Technical Standard, 2006, Extended API Set Part 4.

This reference page is clarified with respect to macros and symbolic constants, and a declaration for the locale_t type is added.

Issue 8

Austin Group Defect 986 is applied, adding strlcat() and strlcpy().

Austin Group Defect 1061 is applied, adding memmem().