逐行读取文件的已知结构，但长度未知

Question

I'm sorry to ask this question, because I found similar answered questions, but I'm having difficulty to understand how to read lines of unknown length but the structure is the same.

Each line is structured by the following: name:id:buyingPrice:sellingPrice:profit:quantity

The names and IDs are strings while the rest are doubles.

My problem is I don't know how to setup a while that reads and stores each field, would it be possible to get a detailed explanation on how to accomplish this?

Here's my read of the file(just with strings) :

file = fopen("fileData.txt", "rt");

if(file != NULL){
    char lineSize[128] = "";

    while(fgets(line, 128, file) != NULL){
        fscanf("%s:%s:%s:%s:%s:%s", string1, string2, string3, string4, string5, string6);

    }
    fclose(file);

Answer 1

你有没有想过使用strtok解析后的标记fgets ？

Answer 2

What I would use is the 'a' modifier for the scanf-format: Simply say 'fscanf("%as:%as:...", ...)', pass in the addresses of unallocated pointers and let fscanf malloc them for you.

This originated as a gnu extension, but AFAIK, it has made it into the C11 standart.