string.h(3)                POSIX Programmer's Manual               string.h(3)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       string.h -- string operations

SSYYNNOOPPSSIISS
       #include <string.h>

DDEESSCCRRIIPPTTIIOONN
       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 POSIX.1-2017, _S_e_c_t_i_o_n _2_._2,
       _T_h_e _C_o_m_p_i_l_a_t_i_o_n _E_n_v_i_r_o_n_m_e_n_t) to enable the visibility of these symbols
       in this header.

       The _<_s_t_r_i_n_g_._h_> header shall define NULL and ssiizzee__tt as described in
       _<_s_t_d_d_e_f_._h_>.

       The _<_s_t_r_i_n_g_._h_> header shall define the llooccaallee__tt type as described in
       _<_l_o_c_a_l_e_._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.


           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    *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 *);
           int      strcoll_l(const char *, const char *, locale_t);
           char    *strcpy(char *restrict, const char *restrict);
           size_t   strcspn(const char *, const char *);
           char    *strdup(const char *);
           char    *strerror(int);
           char    *strerror_l(int, locale_t);
           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    *strndup(const char *, size_t);
           size_t   strnlen(const char *, size_t);
           char    *strpbrk(const char *, const char *);
           char    *strrchr(const char *, int);
           char    *strsignal(int);
           size_t   strspn(const char *, const char *);
           char    *strstr(const char *, const char *);
           char    *strtok(char *restrict, const char *restrict);
           char    *strtok_r(char *restrict, const char *restrict, char **restrict);
           size_t   strxfrm(char *restrict, const char *restrict, size_t);
           size_t   strxfrm_l(char *restrict, const char *restrict,
                        size_t, locale_t);

       Inclusion of the _<_s_t_r_i_n_g_._h_> header may also make visible all symbols
       from _<_s_t_d_d_e_f_._h_>.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       <<llooccaallee..hh>>, <<ssttddddeeff..hh>>, <<ssyyss__ttyyppeess..hh>>

       The System Interfaces volume of POSIX.1-2017, _S_e_c_t_i_o_n _2_._2, _T_h_e
       _C_o_m_p_i_l_a_t_i_o_n _E_n_v_i_r_o_n_m_e_n_t, _m_e_m_c_c_p_y(), _m_e_m_c_h_r(), _m_e_m_c_m_p(), _m_e_m_c_p_y(),
       _m_e_m_m_o_v_e(), _m_e_m_s_e_t(), _s_t_r_c_a_t(), _s_t_r_c_h_r(), _s_t_r_c_m_p(), _s_t_r_c_o_l_l(), _s_t_r_c_p_y(),
       _s_t_r_c_s_p_n(), _s_t_r_d_u_p(), _s_t_r_e_r_r_o_r(), _s_t_r_l_e_n(), _s_t_r_n_c_a_t(), _s_t_r_n_c_m_p(),
       _s_t_r_n_c_p_y(), _s_t_r_p_b_r_k(), _s_t_r_r_c_h_r(), _s_t_r_s_i_g_n_a_l(), _s_t_r_s_p_n(), _s_t_r_s_t_r(),
       _s_t_r_t_o_k(), _s_t_r_x_f_r_m()

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                          string.h(3)
