[ Oracle @ jumper Oracle ] $ man toupper
toupper(3) Linux程序手册(3)3)。
名字
toupper，to lower-convertlettertoupperorlowercase
同步
#includeinttoupper(intc )；
inttolower(intc )；
描述
toupper (convertstheletterctouppercase，if possible )。
to lower (convertstheletterctolowercase，if possible )。
If c is not an unsigned char value，or EOF，the behaviour of these
functions is undefined
RETURN VALUE
thevaluereturnedisthatoftheconvertedletter，or c if the conver-
sion was not possible
确认到
BUGS
thedetailsofwhatconstitutesanuppercaseorlowercaseletterdepend
on the current locale. For example，the default 'C' locale does not
know about umlauts，so no conversion is done for them。
In some non - English locales，therearelowercaseletterswithnocor -
responding uppercase equivalent； the German sharp s is one example。
SEE ALSO
isalpha(3)、setlocale(7(3)、locale )7) )。
GNU 1993-04-04拓扑(3) )。