| Routine |
Attributes |
Description |
| isalnum |
reentrant |
Tests for an alphanumeric character |
| isalpha |
reentrant |
Tests for an alphabetic character |
| iscntrl |
reentrant |
Tests for a Control character |
| isdigit |
reentrant |
Tests for a decimal digit |
| isgraph |
reentrant |
Tests for a printable character with the exception of space |
| islower |
reentrant |
Tests for a lowercase alphabetic character |
| isprint |
reentrant |
Tests for a printable character |
| ispunct |
reentrant |
Tests for a punctuation character |
| isspace |
reentrant |
Tests for a whitespace character |
| isupper |
reentrant |
Tests for an uppercase alphabetic character |
| isxdigit |
reentrant |
Tests for a hexadecimal digit |
| toascii |
reentrant |
Converts a character to an ASCII code |
| toint |
reentrant |
Converts a hexadecimal digit to a decimal value |
| tolower |
reentrant |
Tests a character and converts it to lowercase if it is uppercase |
| _tolower |
reentrant |
Unconditionally converts a character to lowercase |
| toupper |
reentrant |
Tests a character and converts it to uppercase if it is lowercase |
| _toupper |
reentrant |
Unconditionally converts a character to uppercase |
The character conversion and classification routines allow you to test individual characters for a variety of attributes and convert characters to different formats.
The _tolower, _toupper, and toascii routines are implemented as macros. All other routines are implemented as functions. All macro definitions and function prototypes are found in the CTYPE.H include file.