C编程 - 从文本文件中读取特定的行

问题描述 投票:8回答:2

这里是 编码:

int main()
{
    struct vinnaren
    {
        char vinnare[20];
        int artal;
    };
    struct vinnaren v[10];
    int inputrader;
    int antalrader;  //I want antalrader to be equal to the first 
                     //line in test.txt(the first line is "5")
    char file_name[256] = "test.txt";
    char buf[512];
    FILE *f = fopen(file_name, "r");
    if (!f)
    {
        exit(0);
    }
    while (fgets(buf, sizeof buf, f))
    {

        printf("%s", buf);
    }
    fclose(f);
}

这是我的代码。我想在文件test.txt中让antalrader = line1如何从文件中读取特定的行?

c file-io
2个回答
17
投票

有了这段代码,你可以逐行读取文件,从而从文本文件中读取特定的行。

lineNumber = x;

static const char filename[] = "file.txt";
FILE *file = fopen(filename, "r");
int count = 0;
if ( file != NULL )
{
    char line[256]; /* or other suitable maximum line size */
    while (fgets(line, sizeof line, file) != NULL) /* read a line */
    {
        if (count == lineNumber)
        {
            //use line or in a function return it
            //in case of a return first close the file with "fclose(file);"
        }
        else
        {
            count++;
        }
    }
    fclose(file);
}
else
{
    //file doesn't exist
}

0
投票

我得到了一个非常简单的答案 但我不知道它是否能帮助到任何人:

int OpenCommand(int idOfCommand)
{
    fscanf(file_ptr, "%[^idOfCommand]",a[idOfCommand]);
    printf("%d\n", a[idOfCommand]);
    system("pause");

    return 0;
}
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