链表的头指针 front 指向新插入的节点 s 的下一个节点，而 s 的指针意思指向原来的头节点是什么

在C语言中打开图片需要使用图像处理库。常用的图像处理库包括OpenCV、ImageMagick、FreeImage等。以下是使用OpenGL库打开并显示一张bmp图片的代码(需要安装OpenGL和GLUT库)：

#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>

int width = 500, height = 500;

void display(void) {
    glClear(GL_COLOR_BUFFER_BIT);
    glFlush();
}

int main(int argc, char** argv) {
    FILE* fp;
    char fname[] = "image.bmp";
    unsigned char header[54];
    unsigned int dataPos, size, width, height;
    unsigned char* data;

    fp = fopen(fname, "rb");
    fread(header, sizeof(unsigned char), 54, fp);
    dataPos = *(int*)&header[10];
    size = *(int*)&header[34];
    width = *(int*)&header[18];
    height = *(int*)&header[22];
    data = (unsigned char*)malloc(sizeof(unsigned char) * size);

    fread(data, sizeof(unsigned char), size, fp);
    fclose(fp);

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(width, height);
    glutCreateWindow(fname);

    glClearColor(0.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);

    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, width, 0, height);

    glRasterPos2i(0, 0); // set position of the image
    glDrawPixels(width, height, GL_BGR_EXT, GL_UNSIGNED_BYTE, data); // draw image

    glutDisplayFunc(display);
    glutMainLoop();

    free(data);
    return 0;
}

该程序读取位图文件image.bmp并使用OpenGL库绘制该图片。可以将该程序保存为image.c并在命令行中执行：

gcc -o image image.c -lGL -lGLU -lglut
./image

即可打开该图片。