string.h - string operations
#include <string.h>
[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, Section 2.2, The Compilation Environment) 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>.
None.
None.
None.
<stddef.h>, <sys/types.h>, the System Interfaces volume of IEEE Std 1003.1-2001, memccpy(), memchr(), memcmp(), memcpy(), memmove(), memset(), strcat(), strchr(), strcmp(), strcoll(), strcpy(), strcspn(), strdup(), strerror(), strlen(), strncat(), strncmp(), strncpy(), strpbrk(), strrchr(), strspn(), strstr(), strtok(), strxfrm()
First released in Issue 1. Derived from Issue 1 of the SVID.
The DESCRIPTION is updated for alignment with the POSIX Threads Extension.
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.