[fpc-pascal] options for better performance & declaration of system procedures
jonas.maebe at elis.ugent.be
Thu Sep 24 10:58:16 CEST 2009
On 24 Sep 2009, at 10:53, 章宏九 wrote:
> 2009/9/24 Jonas Maebe <jonas.maebe at elis.ugent.be>:
>>> I would like also to know the situation in C. (I mean
>>> declaration of printf and scanf. Are they implemented in glibc or
>> In glibc.
> Unlike pascal?
Yes and no. In both Pascal and C, the internal functionality of the
read/write (scan/print) code is in the run time library. However
a) in Pascal, the compiler parses the types that you pass to the read/
write code and directly calls the appropriate helper routines
b) in C, the types are specified in the format string and the run time
library itself determines the actual types at run time
So scanf/printf are more complex than the Pascal read/write routines.
FPC and Delphi nowadays also have printf/scanf-style routines though.
They are called format and scanf (part of the sysutils unit).
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