The header contains functions for testing and converting
characters. In the following list, the declaration of each
function is followed by a description of the value returned
by each function. Note - a return value of !=0 (non-zero)
implies true when used in a conditional statement.
| 1 |
int isalnum(int c); |
!=0 if c is an alphanumeric character
in range 'A'-'Z', 'a'-'z', '0'-'9' |
| 2 |
int isalpha(int c); |
!=0 if c is an alphabetic character is range 'A'-'Z',
'a'-'z' |
| 3 |
int iscntrl(int c); |
!=0 if c is a control character in range 0x0-0x1F
or 0x7F |
| 4 |
int isdigit(int c); |
!=0 if c is a digit in range '0'-'9' |
| 5 |
int isgraph(int c); |
!=0 if c is a printable character (excluding space)
in range 0x21-0x7E |
| 6 |
int islower(int c); |
!=0 if c is lower case letter in range 'a'-'z' |
| 7 |
int isprint(int c); |
!=0 if c is a printable character in range 0x20-0x7E |
| 8 |
int ispunct(int c); |
!=0 if c is a punctuation character in range 0x21-0x2F,
0x3A-0X40, 0X5B-0X60, 0X7B-0X7E |
| 9 |
int isspace(int c); |
!=0 if c is a white space character in range 0x9-0xD
or 0x20 |
| 10 |
int isupper(int c); |
!=0 if c is upper case letter in range 'A'-'Z' |
| 11 |
int isxdigit(int c); |
!=0 if c is a hexadecimal digit in range '0'-'9',
'A'-'F', 'a'-'f' |
| 12 |
int tolower(int c); |
return lower case value of character c in range 'a'-'z' |
| 13 |
int toupper(int c); |
return upper case value of character c in range 'A'-'Z' |
| |
|
|
