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C預編譯宏

class copy lin turn -- urn ces stdio.h std

/*
 ============================================================================
 Name        : c_test001.c
 Author      : jiftle
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 
*/ #include <stdio.h> #include <stdlib.h> #define YEAR ((((__DATE__ [7] - ‘0‘) * 10 + (__DATE__ [8] - ‘0‘)) * 10 + (__DATE__ [9] - 0)) * 10 + (__DATE__ [10] - 0)) #define MONTH (__DATE__ [2] == ‘n‘ ? 0 \ : __DATE__ [2] == b ? 1 : __DATE__ [2] == r ? (__DATE__ [0] ==
M ? 2 : 3) : __DATE__ [2] == y ? 4 : __DATE__ [2] == n ? 5 : __DATE__ [2] == l ? 6 : __DATE__ [2] == g ? 7 : __DATE__ [2] == p ? 8 : __DATE__ [2] == t ? 9 : __DATE__ [2] == v ? 10 : 11) #define DAY ((__DATE__ [4] == ‘ ‘ ? 0 : __DATE__ [4] - ‘0‘) * 10 + (__DATE__ [5
] - 0)) #define DATE_AS_INT (((YEAR - 2000) * 12 + MONTH) * 31 + DAY) int main(void) { puts("!!!Hello World!!!"); /* prints !!!Hello World!!! */ printf("%s\n","----------------------------------"); printf("%-30s = %10d\n","__STDC_HOSTED__",__STDC_HOSTED__); printf("%-30s = %10d\n","__STDC_VERSION__",__STDC_VERSION__); printf("%-30s = %10d\n","__STDC__",__STDC__); printf("%-30s = %10s\n","__DATE__",__DATE__); printf("%-30s = %10s\n","__TIME__",__TIME__); printf("build time: %d-%02d-%02d %s\n",YEAR, MONTH + 1, DAY,__TIME__); return EXIT_SUCCESS; }

linux下,gcc 運行結果:

----------------------------------
__STDC_HOSTED__ = 1
__STDC_VERSION__ = 201112
__STDC__ = 1
__DATE__ = Jun 22 2017
__TIME__ = 11:08:59
build time: 2017-01-22 11:08:59

C預編譯宏