Shell Programming and Scripting

/* date_d.c  YYYY-MM-DD format */
/* compile: cc date_d.c -o date_d
*  usage:   date_d 2007-08-17
*           echo "2007-08-17" | date_d
*  ouput from example: 228
*/

#include <time.h>
#include <stdio.h>

int process(const char *src)
{
    struct tm tmptr;
    int retval=0;
    
    if(strptime(src, "%Y-%m-%d", &tmptr)!=NULL)    
		retval=tmptr.tm_yday;
	return retval;
}

int main(int argc, char **argv)
{
    char tmp[128]={0x0};
	
	if(argc>1)
	{
	   	int i=0;
		for(i=1; i<argc; i++) 
	   		fprintf(stdout,"%d\n", process(argv[i]));
	}
	else
	{
		while(fgets(tmp, sizeof(tmp), stdin) !=NULL) 		
			fprintf(stdout,"%d\n", process(tmp));
	}   		
    return 0;
}