diff options
| author | Jason Hobbs | 2011-08-23 11:06:52 +0000 |
|---|---|---|
| committer | Wolfgang Denk | 2011-10-17 22:25:34 +0200 |
| commit | 93337abbfe2951c63a4e7b450da1848c6c69217f (patch) | |
| tree | edd9a0d1ce9318fab3aff96bf23a0c69fc91fe8f | |
| parent | c8a2079e49ee15dde10278865425ec9c36215f31 (diff) | |
Add isblank
Existing ctype checks are implemented using a 256 byte lookup table,
allowing each character to be in any of 8 character classes. Since there
are 8 existing character classes without the blank class, I implemented
isblank without using the lookup table. Since there are only two blank
characters - tab and space - this is a more reasonable approach than
doubling the size of the lookup table to accommodate one more class.
Signed-off-by: Jason Hobbs <jason.hobbs@calxeda.com>
| -rw-r--r-- | include/linux/ctype.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/ctype.h b/include/linux/ctype.h index 6dec944a370..42f9305a028 100644 --- a/include/linux/ctype.h +++ b/include/linux/ctype.h @@ -31,6 +31,12 @@ extern const unsigned char _ctype[]; #define isupper(c) ((__ismask(c)&(_U)) != 0) #define isxdigit(c) ((__ismask(c)&(_D|_X)) != 0) +/* + * Rather than doubling the size of the _ctype lookup table to hold a 'blank' + * flag, just check for space or tab. + */ +#define isblank(c) (c == ' ' || c == '\t') + #define isascii(c) (((unsigned char)(c))<=0x7f) #define toascii(c) (((unsigned char)(c))&0x7f) |