ISCNTRL(3)                 POSIX Programmer's Manual                ISCNTRL(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
       iscntrl, iscntrl_l -- test for a control character

SSYYNNOOPPSSIISS
       #include <ctype.h>

       int iscntrl(int _c);
       int iscntrl_l(int _c, locale_t _l_o_c_a_l_e);

DDEESSCCRRIIPPTTIIOONN
       For _i_s_c_n_t_r_l(): The functionality described on this reference page is
       aligned with the ISO C standard. Any conflict between the requirements
       described here and the ISO C standard is unintentional. This volume of
       POSIX.1-2008 defers to the ISO C standard.

       The _i_s_c_n_t_r_l() and _i_s_c_n_t_r_l___l() functions shall test whether _c is a
       character of class ccnnttrrll in the current locale, or in the locale
       represented by _l_o_c_a_l_e, respectively; see the Base Definitions volume of
       POSIX.1-2008, _C_h_a_p_t_e_r _7, _L_o_c_a_l_e.

       The _c argument is a type iinntt, the value of which the application shall
       ensure is a character representable as an uunnssiiggnneedd cchhaarr or equal to the
       value of the macro EOF. If the argument has any other value, the
       behavior is undefined.

       The behavior is undefined if the _l_o_c_a_l_e argument to _i_s_c_n_t_r_l___l() is the
       special locale object LC_GLOBAL_LOCALE or is not a valid locale object
       handle.

RREETTUURRNN VVAALLUUEE
       The _i_s_c_n_t_r_l() and _i_s_c_n_t_r_l___l() functions shall return non-zero if _c is a
       control character; otherwise, they shall return 0.

EERRRROORRSS
       No errors are defined.

       _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_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       To ensure applications portability, especially across natural
       languages, only these functions and the functions in the reference
       pages listed in the SEE ALSO section should be used for character
       classification.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _i_s_a_l_n_u_m(), _i_s_a_l_p_h_a(), _i_s_b_l_a_n_k(), _i_s_d_i_g_i_t(), _i_s_g_r_a_p_h(), _i_s_l_o_w_e_r(),
       _i_s_p_r_i_n_t(), _i_s_p_u_n_c_t(), _i_s_s_p_a_c_e(), _i_s_u_p_p_e_r(), _i_s_x_d_i_g_i_t(), _s_e_t_l_o_c_a_l_e(),
       _u_s_e_l_o_c_a_l_e()

       The Base Definitions volume of POSIX.1-2008, _C_h_a_p_t_e_r _7, _L_o_c_a_l_e,
       <<ccttyyppee..hh>>, <<llooccaallee..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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                  2013                           ISCNTRL(3)
