一行一行读取文件文本内容

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

int main(void)
{
    const char *fopen_file = "/usr/local/etc/MiniGUI.cfg";
    FILE* fp = NULL;
    #define LINE_BUF_MAX 1024
    char line_buf[LINE_BUF_MAX];
    int line_buf_len;
    int cur = 0;

    fp = fopen (fopen_file, "r");

    for (;;) {
        fgets(line_buf, LINE_BUF_MAX, fp);
        if (feof (fp)) break;

        if (cur++ & 0x4) {
            cur = 0;
            line_buf_len = strlen(line_buf);
            fseek (fp, -line_buf_len, SEEK_CUR); // 缓冲区向后退line_buf_len字节,放弃该行
            // 下一次执行fgets会继续读取到该行
        }

        printf("<%03d> %s", cur, line_buf);
        usleep(50*1000);
    }
}