读取文件

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int main(){
    FILE *fp = fopen("tmp.csv", "r");
    if(fp == NULL){
        printf("read file failed\n");
        exit(EXIT_FAILURE);
    }
    char row[80];
    char *token;
    while (fgets(row, 80, fp)!=NULL)    // 从 stram 中读取数据，每次读取一行，到 EOF 结束
    {
        printf("Row: is %s", row);
        token = strtok(row, ",");
        while (token!=NULL)
        {
            printf("Token: %s\n", token);
            token = strtok(NULL, ",");
        } 
    }
    fclose(fp);
    return 0;
}

Output:
Row: is 2023-05-30-18:15:10,1685441710444,29,20,91,80,20,10,40,20,95,90,81,69
Token: 2023-05-30-18:15:10
Token: 1685441710444
Token: 29
Token: 20
Token: 91
Token: 80
Token: 20
Token: 10
Token: 40
Token: 20
Token: 95
Token: 90
Token: 81
Token: 69

写入文件

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int main(){
    FILE *fp = fopen("tmp.csv", "w");
    if(fp == NULL){
        printf("read file failed\n");
        exit(EXIT_FAILURE);
    }

    fprintf(fp, "%s,%s,%s\n", "2023-05-30-18:15:57", "1685441757081", "100");

    fclose(fp);

    return 0;
}

这种方法是直接覆盖掉源文件