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io - 使用fgets和strtok在C中读取CSV文件仅读取第一列

发布于 2020-03-27 11:05:13

我有一个.csv文件,看起来像

Config,Prob,MAN,ATL,CVERT,TVERT,LVERT,PELV,SAC,RIB,SCAP,PHUM,DHUM,PRAD,DRAD,CARP,PMC,DMC,PHX,PFEM,DFEM,PTIB,DTIB,TARS,PMT,DMT
LH,1,2,2,7,13,6,2,1,13,2,2,2,1,1,6,2,2,24,2,2,2,2,8,2,2
LH,1,0,0,0,0,0,0,0,9,1,2,2,2,2,12,2,2,18,1,1,1,1,4,1,1
LH,1,2,2,7,3,0,2,1,3,1,1,1,1,1,6,1,1,6,0,0,0,0,0,0,0
LH,1,0,0,0,13,6,2,1,8,0,2,2,1,1,0,0,0,0,0,0,0,0,0,0,0
LH,1,2,2,4,13,6,2,1,18,2,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0
LH,1,0,0,0,13,6,2,1,18,2,2,2,0,0,0,0,0,0,2,2,0,0,0,0,0
LH,3,0,0,0,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
LH,1,0,0,0,13,6,2,1,24,2,2,2,2,2,12,2,2,24,2,2,2,2,8,2,2
LH,1,0,0,1,13,3,2,1,15,2,0,0,2,2,0,0,0,6,2,2,2,2,0,0,0
LH,1,0,0,0,0,0,0,0,10,0,1,1,0,0,0,0,0,18,0,0,0,0,0,0,0
LH,1,0,2,7,3,0,0,0,7,2,2,2,2,2,12,2,2,24,2,2,2,2,8,2,2
LH,1,0,0,2,0,0,0,0,14,1,2,2,2,2,0,0,0,18,2,2,2,2,0,0,0
LK,1,0,0,0,0,0,0,0,13,0,0,0,1,1,6,0,0,0,0,0,0,0,0,0,0
LK,1,2,2,7,13,6,2,1,17,1,0,0,0,0,0,0,0,6,1,1,1,1,4,1,1
LK,1,0,0,0,10,6,0,0,23,1,1,1,1,1,6,1,1,18,2,2,2,2,8,2,2
LK,1,2,2,7,0,0,0,0,18,2,0,0,1,1,12,2,2,24,2,2,2,2,8,2,2
LK,1,0,0,3,0,0,0,0,8,0,0,0,2,2,12,2,2,24,2,2,2,2,8,2,2
LK,1,2,2,7,0,0,0,0,8,0,0,0,2,2,12,2,2,24,0,0,2,2,8,2,2
LK,3,2,2,7,13,6,2,1,22,2,2,2,2,2,12,2,2,24,2,2,2,2,8,2,2
LK,1,2,2,7,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
LK,1,2,2,6,0,3,0,0,11,0,2,2,0,0,12,2,2,18,0,0,0,0,8,2,2
LK,1,2,2,7,13,6,2,1,16,2,1,1,2,2,12,2,2,6,2,2,2,2,8,2,2
LK,1,2,0,0,10,6,2,1,19,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
LK,1,2,2,5,13,6,2,1,12,1,0,0,0,0,12,2,2,6,0,0,0,0,8,2,2

我想忽略文本,只取数字。这是我的代码:

    int arr[rows][columns]; /* rows/columns of .csv file */
    char buf[1000];
    int r = 0;

    while (fgets(buf,1000,ifp)) {
        char read = 'N';
        const char *tok;
        int ret =0;
        int c = 0;
        int count = 0;
        char *ptr;
        printf("%s \n", buf);

        for (tok = strtok(buf, ","); tok && *tok; tok = strtok(NULL, ",\n")){
                printf("%s ", buf); /* replace buf with tok */
                if(isNumber(tok)==1){
                    read = 'Y';
                    ret = strtol(tok,&ptr,10);
                    arr[r][c] = ret;
                    c++;
                    printf("Entered ");
                    //printf("%ld ", arr[r][c]);
                }
                if(strtok(NULL,"\n") && read == 'N')
                    count++;
        }
        r++;
        //r -= count;
    }

isNumber本质上是isdigt预期的扩展和工作。但是,无论何时tok为每次迭代打印输出,它都会在第一个逗号之后停止。样本输出:Config LH LH LH LH LH LH LH LH LH LH LH LH LK LK LK LK LK LK LK LK LK LK LK LK似乎可以很好地读取输入内容fgets,因为它会打印出.csv文件的每一行。所以看来问题出在我的for循环上。看来我不正确地增加了令牌。

尝试另一个示例:

    char alph[] = "a-b-c-e";
    for (const char *tok = strtok(alph, "-"); tok && *tok; tok = strtok(NULL, "-\0")){
        printf("%s ", tok);
    }

yields:, a b c e这是正确的结果。因此,我感觉我在解析文件时缺少某些东西。任何帮助表示赞赏。谢谢。

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提问者
hkj447
被浏览
52
Jonathan Leffler 2019-07-03 22:24

您的循环是:

 for (tok = strtok(buf, ","); tok && *tok; tok = strtok(NULL, ",\n")) 
 {
     …omitted…
     if (strtok(NULL, "\n") && read == 'N')
         count++;
 }

您有3个呼叫strtok(),而其中1 个呼叫if占用了换行符的所有内容。我不确定你在想什么。看来您应该忽略这一点strtok()-但我不确定您需要用什么替换它。

由于循环控件中的第二个调用读取到换行符或逗号(strtok(NULL, ",\n")),因此您无法确定何时到达行尾,除非将tok其设置NULL为表示不再有令牌。

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