iscntrl - cppreference.com (original) (raw)

| | | | | ---------------------- | | | | int iscntrl( int ch ); | | |

Checks if the given character is a control character, i.e., codes [0x00, 0x1F] and 0x7F.

The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.

[edit] Parameters

ch - character to classify

[edit] Return value

Non-zero value if the character is a control character, zero otherwise.

[edit] Example

#include <ctype.h> #include <locale.h> #include <stdio.h>   int main(void) { unsigned char c = '\x94'; // the control code CCH in ISO-8859-1 printf("In the default C locale, \x94 is %sa control character\n", iscntrl(c) ? "" : "not " ); setlocale(LC_ALL, "en_GB.iso88591"); printf("In ISO-8859-1 locale, \x94 is %sa control character\n", iscntrl(c) ? "" : "not " ); }

Possible output:

In the default C locale, \x94 is not a control character In ISO-8859-1 locale, \x94 is a control character

[edit] References

[edit] See also

ASCII values characters iscntrl iswcntrl isprint iswprint isspace iswspace isblank iswblank isgraph iswgraph ispunct iswpunct isalnum iswalnum isalpha iswalpha isupper iswupper islower iswlower isdigit iswdigit isxdigit iswxdigit
decimal hexadecimal octal
0–8 \x0–\x8 \0–\10 control codes (NUL, etc.) ≠0 0 0 0 0 0 0 0 0 0 0 0
9 \x9 \11 tab (\t) ≠0 0 ≠0 ≠0 0 0 0 0 0 0 0 0
10–13 \xA–\xD \12–\15 whitespaces (\n, \v, \f, \r) ≠0 0 ≠0 0 0 0 0 0 0 0 0 0
14–31 \xE–\x1F \16–\37 control codes ≠0 0 0 0 0 0 0 0 0 0 0 0
32 \x20 \40 space 0 ≠0 ≠0 ≠0 0 0 0 0 0 0 0 0
33–47 \x21–\x2F \41–\57 !"#$%&'()*+,-./ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
48–57 \x30–\x39 \60–\71 0123456789 0 ≠0 0 0 ≠0 0 ≠0 0 0 0 ≠0 ≠0
58–64 \x3A–\x40 \72–\100 :;<=>?@ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
65–70 \x41–\x46 \101–\106 ABCDEF 0 ≠0 0 0 ≠0 0 ≠0 ≠0 ≠0 0 0 ≠0
71–90 \x47–\x5A \107–\132 GHIJKLMNOPQRSTUVWXYZ 0 ≠0 0 0 ≠0 0 ≠0 ≠0 ≠0 0 0 0
91–96 \x5B–\x60 \133–\140 [\]^_` 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
97–102 \x61–\x66 \141–\146 abcdef 0 ≠0 0 0 ≠0 0 ≠0 ≠0 0 ≠0 0 ≠0
103–122 \x67–\x7A \147–\172 ghijklmnopqrstuvwxyz 0 ≠0 0 0 ≠0 0 ≠0 ≠0 0 ≠0 0 0
123–126 \x7B–\x7E \173–\176 {|}~ 0 ≠0 0 0 ≠0 ≠0 0 0 0 0 0 0
127 \x7F \177 backspace character (DEL) ≠0 0 0 0 0 0 0 0 0 0 0 0