使用sscanf解析CSV文件出现垃圾值，求问题原因及解决

问题重现 #

尝试用sscanf解析CSV文件，编写了checkString函数检测行首引号，但运行后输出出现00doA这类垃圾值，相关代码、CSV内容及异常输出如下：

检测函数代码 #

int checkString(const char *str) {
    if (str[0] == '"') {
        return 1;
    }
    return 0;
}

主函数代码 #

int main() {
    char inputLine[100]; //input line
    Node *pList = NULL; //initialize linked list
    FILE *inputStream = fopen("../musicPlayList.csv", "r");
    Record testArr[100];
    Record inputRecord;
    Duration inputDuration;
    int inputTimesPlayed = 0;
    int inputRating = 0;

    char artistToken[20];
    char albumTitleToken[20];
    char songTitleToken[20];
    char genreToken[20];
    char durationToken[20];
    char timesPlayedToken[20];
    char ratingToken[20];

    if (inputStream != NULL) {
        while (fgets(inputLine, sizeof(inputLine), inputStream) != NULL) {
            if (checkString(inputLine)) {
                sscanf(inputLine, "\"%[^\"]\" %s %s %s %s %s %s",
                       artistToken, albumTitleToken,
                       songTitleToken, genreToken, durationToken,
                       timesPlayedToken, ratingToken);
            } else {
                sscanf(inputLine, "%s %s %s %s %s %s %s",
                       artistToken, albumTitleToken,
                       songTitleToken, genreToken, durationToken,
                       timesPlayedToken, ratingToken);
            }
            printf("%s %s %s %s %s %s %s\n",
                   artistToken, albumTitleToken, songTitleToken,
                   genreToken, durationToken, timesPlayedToken,
                   ratingToken);
        }
    }

    return 0;
}

CSV文件内容 #

"Swift, Taylor",1989,Shake it Off,Pop,3:35,12,3
Drake,NOTHING WAS THE SAME,Own it,Rap,3:23,3,3
Drake,YOU WELCOME,The Motto,Rap,4:13,7,4
"Perri, Christina",HEAD OF HEART,Trust,Pop,2:35,3,5
"Bieber, Justin",PURPOSE,No Sense,Pop,4:12,6,1
Eminem,SHADYXV,Vegas,Rap,3:37,8,3
Adele,25,Remedy,Pop,4:11,24,4
"Swift, Taylor",RED,Stay Stay Stay,Pop,4:42,5,1
"Brooks, Garth",FRESH HORSES,The Old Stuff,Country,2:57,11,2

异常输出 #

Swift, Taylor ,1989 , Shake it Off, Pop, 3:35,12,3 00doA
Drake, NOTHING WAS THE SAME, Own it, Rap, 3:23,3, 3
Drake, YOU WELCOME, The Motto, Rap, 4:13,7,4 SAME, Own it, Rap, 3:23,3,3
Perri, Christina ,HEAD ,3,5 HEART, Trust, Pop,2:35,3,5 it, Rap, 3:23,3,3
Bieber, Justin ,PURPOSE, No Sense, Pop, 4:12,6,1 HEART, Trust, Pop, 2:35Sense, Pop, 4:12,6,1 it, Rap, 3:23, 3, 3
Eminem, SHADYXV, Vegas, Rap, 3:37,8,3 , PURPOSE, No Sense, Pop, 4:12,6,1 HEART, Trust, Pop, 2:35Sense, Pop, 4:12,6,1 it, Rap, 3:23,3, 3
Adele, 25, Remedy, Pop, 4:11, 24,4 , PURPOSE, No Sense, Pop, 4:12,6,1 HEART, Trust, Pop, 2:35Sense, Pop, 4:12,6,1 it, Rap, 3:23,3 , 3
Swift, Taylor ,RED, Stay Stay Stay, Pop, 4:42,5,1 it, Rap, 3:23,3, 3
Brooks, Garth ,FRESH HORSES, The 1,2 Stuff, Country,2:57, 11, 2

Process finished with exit code 0

问题原因 #

1. 分隔符匹配错误：CSV的字段分隔符是逗号，但你的sscanf格式字符串用空格作为分隔依据。比如第一行解析完引号内容后，会把,1989当成一个完整字段读入，后续所有字段全部错位，未被覆盖的内存旧数据或随机值就会被输出。

2. 字符数组未初始化：定义的artistToken等字符数组没有初始化，第一次循环时如果sscanf没有完全覆盖数组内容，剩余位置会保留内存中的随机垃圾值（比如00doA）。

3. 带空格字段解析失败：像Shake it Off、NOTHING WAS THE SAME这类包含空格的字段，%s格式符只会读取到第一个空格就停止，导致字段被截断，后续解析彻底混乱，旧数据残留输出。

4. 引号后逗号未处理：在带引号的行中，格式字符串"\"%[^\"]\" %s..."解析完引号内容后，直接用空格匹配，但实际引号后是逗号（比如"Swift, Taylor",1989），逗号不是空格，导致后续字段全部错位，残留数据被打印。

内容的提问来源于stack exchange，提问作者sangregoriokimpo