#include <stdlib.h> #include <stdio.h> using namespace std; int main(){ FILE *infile,*outfile; long a; double b, c, sum=0; char d; infile = fopen("input.txt", "r"); outfile = fopen("output.txt", "a"); if(infile == NULL && outfile == NULL){ printf("Files DOES NOT EXISTS!"); } else{ while(feof(infile)== 0) { fscanf(infile, "%ld %lf %lf", &a, &b, &c); printf("%ld %.3f %.3f\n", a, b, c); fprintf(outfile,"%ld %.3f %.3f\n", a, b, c); sum = a + b + c; } } printf("sum is %.3f\n", sum); fprintf(outfile,"sum is %.3f\n", sum); fclose(infile); fclose(outfile); system("pause"); }

Output.txt

                5 2.215 21.220 6 6.100 57.220 7 8.000 9.000 10 11.000 12.000 sum is 33.000

【另類讀入方式】一次讀入一行文字，再用sscanf()將讀入的文字，進行格式化分割。

輸入檔；

scholar.in

            123 223 1234 234 234 4321

程式碼：

                  #include <stdlib.h> #include <stdio.h> using namespace std; int main(){ char buff[BUFSIZ]; int a,b,c; FILE *input= fopen("d:\\temp\\scholar.in", "r+"); if (input==NULL) perror ("Error opening file"); else{ while(feof(input)== 0){ while ( fgets( buff, sizeof buff, input ) != NULL ) { if ( sscanf( buff, "%d %d %d", &a, &b, &c ) == 3 ) { printf("%d %d %d\n",a,b,c); } } } } fclose(input); system("pause"); }