<ctype.h>: Character Operations

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Detailed Description

These functions perform various operations on characters.

 #include <ctype.h>

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Function Documentation

int isalnum

(

int

__c

)

Checks for an alphanumeric character. It is equivalent to (isalpha(c) || isdigit(c)).

int isalpha

(

int

__c

)

Checks for an alphabetic character. It is equivalent to (isupper(c) || islower(c)).

int isascii

(

int

__c

)

Checks whether c is a 7-bit unsigned char value that fits into the ASCII character set.

int isblank

(

int

__c

)

Checks for a blank character, that is, a space or a tab.

int iscntrl

(

int

__c

)

Checks for a control character.

int isdigit

(

int

__c

)

Checks for a digit (0 through 9).

int isgraph

(

int

__c

)

Checks for any printable character except space.

int islower

(

int

__c

)

Checks for a lower-case character.

int isprint

(

int

__c

)

Checks for any printable character including space.

int ispunct

(

int

__c

)

Checks for any printable character which is not a space or an alphanumeric character.

int isspace

(

int

__c

)

Checks for white-space characters. For the avr-libc library, these are: space, form-feed ('\f'), newline ('\n'), carriage return ('\r'), horizontal tab ('\t'), and vertical tab ('\v').

int isupper

(

int

__c

)

Checks for an uppercase letter.

int isxdigit

(

int

__c

)

Checks for a hexadecimal digits, i.e. one of 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F.

int toascii

(

int

__c

)

Converts c to a 7-bit unsigned char value that fits into the ASCII character set, by clearing the high-order bits.

Warning:

Many people will be unhappy if you use this function. This function will convert accented letters into random characters.

int tolower

(

int

__c

)

Converts the letter c to lower case, if possible.

int toupper

(

int

__c

)

Converts the letter c to upper case, if possible.