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Printf question (newbie)

Jean Paul Talledo Vilela

I want to print in a terminal the "%"character when I put

printf(" %c % ",var);

the % doesn't print

why??

Parents
  • 0 in reply to Dan Henry

    I test both of the senctence in TC

    printf("%c%%",'c');
printf("%c\%",'c');
    the same result
    c%
    but they didn't work in Keil C
    In fact,I never used printf() in keil C.
    At the printf() sentence,it couldn't jump out,as TI never became 1.
    what's the reason?
    I watch the seria port
    Bauld 9600,8bit data

Reply
  • 0 in reply to Dan Henry

    I test both of the senctence in TC

    printf("%c%%",'c');
printf("%c\%",'c');
    the same result
    c%
    but they didn't work in Keil C
    In fact,I never used printf() in keil C.
    At the printf() sentence,it couldn't jump out,as TI never became 1.
    what's the reason?
    I watch the seria port
    Bauld 9600,8bit data

Children
  • 0 in reply to Nocky Tian

    If you are getting "c%" from

    printf("%c\%",'c');
    as compiled by your compiler, don't count on the same results from all compilers. By using "\%", you are in an "undefined" area of the C language. From H&S:

    If the character following the backslash is neither an octal digit, the letter x, nor one of the character escape codes (i.e., n t b r f v \ ' " a ?), the result is undefined.

  • 0 in reply to Nocky Tian

    "At the printf() sentence,it couldn't jump out,as TI never became 1.
    what's the reason?"

    Purely a guess, since you have not shown your UART initialization code, but your UART is not initialized properly or you have not set the TI bit in initialization (as required by Keil's putchar routine, presuming that's what you are using).