<tag/Function/Check if a given character is a letter or digit.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isalnum (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a letter or digit. The return value is non zero if the character
-is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a letter or digit. The return value is zero if the character is anything
+else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a letter.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isalpha (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a letter. The return value is non zero if the character is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a letter. The return value is zero if the character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is in the ASCII (0..127) range.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isascii (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is in the range 0..127 (the range of valid ASCII characters) and a non zero
-value if not.
+<tag/Description/The function returns a non zero value if the given argument
+is in the range 0..127 (the range of valid ASCII characters) and zero if not.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a space or tab.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isblank (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a space or tab character. The return value is non zero if the character
-is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a space or tab character. The return value is zero if the character is
+anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a control character.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ iscntrl (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a control character. The return value is non zero if the character
-is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a control character. The return value is zero if the character is anything
+else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a digit.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isdigit (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a digit. The return value is non zero if the character is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a digit. The return value is zero if the character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
space).
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isgraph (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a printable character with the exception of space. The return value is non
-zero if the character is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a printable character with the exception of space. The return value is zero
+if the character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a lower case letter.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ islower (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a lower case letter. The return value is non zero if the character is
-anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a lower case letter. The return value is zero if the character is anything
+else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a printable character.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isprint (int c);/
-<tag/Description/The function returns a value of zero if the given argument
+<tag/Description/The function returns a non zero value if the given argument
is a printable character (this includes the space character). The return value
-is non zero if the character is anything else.
+is zero if the character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
space or an alphanumeric character.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ ispunct (int c);/
-<tag/Description/The function returns a value of zero if the given argument
+<tag/Description/The function returns a non zero value if the given argument
is a printable character, but not a space or anything alphanumeric. The return
-value is non zero if the character is anything else.
+value is zero if the character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a a white-space character.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isspace (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a white space character. The return value is non zero if the character is
+<tag/Description/The function returns a non zero value if the given argument
+is a white space character. The return value is zero if the character is
anything else. The standard white space characters are: space, formfeed ('\f'),
newline ('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab
('\v').
<tag/Function/Check if a given character is an upper case letter.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isupper (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is an upper case letter. The return value is non zero if the character is
-anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is an upper case letter. The return value is zero if the character is anything
+else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values
<tag/Function/Check if a given character is a hexadecimal digit.
<tag/Header/<tt/<ref id="ctype.h" name="ctype.h">/
<tag/Declaration/<tt/int __fastcall__ isxdigit (int c);/
-<tag/Description/The function returns a value of zero if the given argument
-is a hexadecimal digit (0..9, a..f and A..F). The return value is non zero
-if the character is anything else.
+<tag/Description/The function returns a non zero value if the given argument
+is a hexadecimal digit (0..9, a..f and A..F). The return value is zero if the
+character is anything else.
<tag/Limits/<itemize>
<item>When compiling with <tt/-Os/ the function is actually a macro. The
inline sequence generated by the macro will not work correctly for values