How to read through data in a file, and pass it to

问题:

Okay. I have a file called "Graduates.txt" in my home directory.
I have a portable program to find the home directory, and I opened the file for reading.
Data in the file looks something like this:

year,firstName,lastName

I need to get this data from this file, and separate it into my struct:

typedef struct alumnus {

    int yearGraduated;
    char firstName[30];
    char lastName[30];

} Alumns;

I have a thought that may or may not work:
A while loop reads through the file, using fgets() to get the data. It then copies it to the struct... but I don't know how to implement any of this.

Sorry if this sounds like dumb question, it most likely is.

回答1:

#include <stdio.h>

typedef struct alumnus {
    int yearGraduated;
    char firstName[30];
    char lastName[30];
}Alumns;

int main(void) {

    Alumns REC1;

    FILE *fptr;
    fptr = fopen("Test.txt", "r");

    fscanf(fptr, "%d,%s,%s", &REC1.yearGraduated, REC1.firstName, REC1.lastName);

    printf("%d, %s, %s", REC1.yearGraduated, REC1.firstName, REC1.lastName);
}

Implemented using dasblinkenlight hint.

回答2:

1. Use fgets to read a line from file
2. Use String Tokenization to separate the individual elements

Use strtok() for the same. e.g

   FILE *fp;
   fp = fopen("path", "r");
   char string[150];
   char *token;

   while(!feof(fp)) {
       if (fgets(string,150,fp)) {
           printf("%s\n", string);
           token=strtok(string,",");
           /*Store this token in your struct(your first element) */ 
       }
   }

3.Remember strtok() is non-reentrant function,so store the results returned from evey function call of strtok();

回答3:

Here is a quick example of reading input, using fopen(), fgets() and strtok() and how to format output using correct format strings: (output shown here)

Edited to show placing values into struct Alums

 #include <ansi_c.h>

typedef struct alumnus {  //Note "alumnus" is not necessary here, you have Alumns 
    int yearGraduated;    //below that will satisfy naming the typedef struct
    char firstName[30];
    char lastName[30];

}Alumns;

Alumns a, *pA;  //Create copy of struct Alumns to use

#define FILE_LOC  "C:\\dev\\play\\file10.txt"

int main(void)
{
    FILE *fp;
    char *tok;
    char input[80];

    pA = &a;  //initialize struct

    fp = fopen(FILE_LOC, "r");  //open file (used #define, change path for your file)
    fgets(input, 80, fp);
    tok = strtok(input, ", \n"); //You can also call strtok in loop if number of items unknown
    pA->yearGraduated= atoi(input); //convert this string in to integer
    tok = strtok(NULL, ", \n");
    strcpy(pA->firstName, tok); //copy next two strings into name variables
    tok = strtok(NULL, ", \n");
    strcpy(pA->lastName, tok);
    //note the format strings here for int, and char *
    printf("age:%d\n First Name: %s\n Last Name: %s\n", 
             pA->yearGraduated, pA->firstName, pA->lastName);
    getchar();  //used so I can see output
    fclose(fp);
    return 0;
}