C语言函数大全--l开头的函数

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    long result;
    long x = -12345678L;
    result= labs(x);
    printf("number: %ld , abs value: %ld\n", x, result);

    long long  resultL;
    long long int xL = -1234567890123456789;
    resultL = llabs(xL);
    printf("The absolute value of %lld is %lld\n", xL, resultL);

    return 0;
}

#include <stdio.h>
#include <math.h>

int main()
{
    int n = 3;
    double x = 3.5, result;
    result = ldexp(x, n);

    float xf = 3.5f, resultf;
    resultf = ldexpf(xf, n);

    long double xL = 3.5L, resultL;
    resultL = ldexpl(xL, n); 

    printf("ldexp(%lf, %d) = %lf\n", x, n, result);
    printf("ldexpf(%f, %d) = %f\n", xf, n, resultf);
    printf("ldexpl(%Lf, %d) = %Lf\n", xL, n, resultL);

    return 0;
}

typedef struct {
    long int quot;  // 商
    long int rem;   // 余数
} ldiv_t;

typedef struct {
    long long int quot;  // 商
    long long int rem;   // 余数
} lldiv_t;

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long int numer = 1234567890;
    long int denom = 987654321;
    ldiv_t result;

    result = ldiv(numer, denom);

    printf("%ld / %ld = %ld, %ld %% %ld = %ld\n", numer, denom, 
        result.quot, numer, denom, result.rem);

    long long int numerL = 1234567890123456789LL;
    long long int denomL = 987654321LL;
    lldiv_t resultL;

    resultL = lldiv(numerL, denomL);

    printf("%lld / %lld = %lld, %lld %% %lld = %lld\n", numerL, denomL,
        resultL.quot, numerL, denomL, resultL.rem);

    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <search.h>

int compare(const void *a, const void *b)
{
    return (*(int*)a - *(int*)b);
}

int main()
{
    int arr[] = {1, 2, 3, 4, 5};
    int n = sizeof(arr) / sizeof(arr[0]);
    for (int i = 0; i < n; i++)
        printf("%d ", arr[i]);

    unsigned int * number = (unsigned int *)&n;
    int key = 2;
    int *result;

    result = (int *)lfind(&key, arr, number, sizeof(int), compare);

    if (result != NULL) {
        printf("\n%d is found at index %lld\n", key, result - arr);
    } else {
        printf("\n%d is not found in the array\n", key);
    }

    return 0;
}

#include <graphics.h>

int main(void)
{
    int gdriver = DETECT, gmode;
    int xmax, ymax;
    
    initgraph(&gdriver, &gmode, "");
    
    setcolor(getmaxcolor());
    xmax = getmaxx();
    ymax = getmaxy();

    // 在(0,0) 和(xmax, ymax)之间画一直线
    line(0, 0, xmax, ymax);

    // 在(0,ymax) 和(xmax, 0)之间画一直线
    line(0, ymax, xmax, 0);

    /* clean up */
    getch();
    closegraph();
    return 0;
}

#include <graphics.h>

int main()
{
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");

    moveto(100, 100);  // 将当前点移动到 (100, 100)
    linerel(50, 0);    // 绘制长度为 50，方向为水平（X 轴正方向）的线段
    linerel(0, 50);    // 绘制长度为 50，方向为垂直（Y 轴正方向）的线段
    linerel(-50, 0);    // 绘制长度为 50，方向为水平（X 轴反方向）的线段
    linerel(0, -50);    // 绘制长度为 50，方向为垂直（Y 轴反方向）的线段

    getch();
    closegraph();

    return 0;
}

#include <graphics.h>

int main()
{
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");

    moveto(100, 100);  // 将当前点移动到 (100, 100)
    lineto(150, 150);  // 绘制一条从当前点到 (150, 150) 的线段
    lineto(200, 100);  // 绘制一条从当前点到 (200, 100) 的线段
    lineto(150, 50);   // 绘制一条从当前点到 (150, 50) 的线段
    lineto(100, 100);   // 绘制一条从当前点到 (150, 50) 的线段

    getch();
    closegraph();

    return 0;
}

#include <stdio.h>
#include <time.h>

int main()
{
    time_t now;
    struct tm *local;

    now = time(NULL);       // 获取当前时间戳
    local = localtime(&now);  // 将当前时间戳转换为本地时间

    printf("Current date and time: %s\n", asctime(local));

    return 0;
}

#include <stdio.h>
#include <fcntl.h>

int main()
{
    int fd;
    char buf[128];
    int nbytes;

    fd = open("test.txt", O_RDWR | O_CREAT, 0666);
    if (fd == -1) {
        perror("open");
        return 1;
    }

    // 加锁
    if (lock(fd, F_LOCK, 0) == -1) {
        perror("lock");
        return 1;
    }

    // 写入数据
    sprintf(buf, "Hello, world!\n");
    nbytes = write(fd, buf, sizeof(buf));
    if (nbytes == -1) {
        perror("write");
        return 1;
    }

    // 解锁
    if (lock(fd, F_ULOCK, 0) == -1) {
        perror("unlock");
        return 1;
    }

    close(fd);

    return 0;
}

#include <stdio.h>
#include <math.h>

int main()
{
    double x = 2.0;
    double result = log(x);

    printf("The natural logarithm of %lf is %lf.\n", x, result);

    return 0;
}

#include <stdio.h>
#include <math.h>

int main()
{
    double x = 100.0;
    double result = log10(x);

    printf("The logarithm base 10 of %lf is %lf.\n", x, result);

    return 0;
}

#include <stdio.h>
#include <setjmp.h>

jmp_buf buf;

void do_something()
{
    printf("do_something() start.\n");

    // 跳转到 setjmp() 处
    longjmp(buf, 1);

    printf("do_something() end.\n");
}

int main()
{
    int val = 0;

    // 设置上下文环境
    if (setjmp(buf) == 0) {
        printf("setjmp() called.\n");
        do_something();
    } else {
        printf("longjmp() called.\n");
        val = 1;
    }

    printf("Program ends with value %d.\n", val);

    return 0;
}

#include <conio.h>

int main(void)
{
	clrscr(); // 清空屏幕
	highvideo(); // 将文本颜色设置为高对比度模式
	cprintf("High Intesity Text\r\n");
	lowvideo(); // 将文本颜色设置为低对比度模式
	gotoxy(1,2); // 将光标移动到指定的坐标 (x, y)，其中 x 和 y 分别为列和行数
	cprintf("Low Intensity Text\r\n");

	return 0;
}

#include <stdlib.h>
#include <stdio.h>

int main()
{
   unsigned long result;
   unsigned long value = 2;

   result = _lrotl(value, 2);
   printf("The value %lu rotated left one bit is: %lu\n", value, result);

   return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <search.h>

int compare(const void *a, const void *b)
{
    return *(int *)a - *(int *)b;
}

int main()
{
    int arr[] = { 3, 1, 4, 1, 5, 9, 2, 6, 5 };
    int len = sizeof(arr) / sizeof(int);

    int key = 5;
    int *result = lsearch(&key, arr, &len, sizeof(int), compare);

    if (result != NULL) {
        printf("Found %d at index %ld.\n", *result, result - arr);
    } else {
        printf("%d not found in the array.\n", key);
    }

    return 0;
}

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

int main()
{
    int fd = open("temp.txt", O_RDWR);
    if (fd == -1) {
        printf("Failed to open the file.\n");
        return -1;
    }

    off_t pos = lseek(fd, 5, SEEK_SET);
    if (pos == -1) {
        printf("Failed to seek the file.\n");
        close(fd);
        return -1;
    }

    char buf[10];
    ssize_t nread = read(fd, buf, 5);
    if (nread == -1) {
        printf("Failed to read the file.\n");
        close(fd);
        return -1;
    }

    buf[nread] = '\0';
    printf("Read %ld bytes from position %ld: %s\n", nread, pos, buf);

    close(fd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long value = 123456789L;
    char str[20];

    ltoa(value, str, 2);
    printf("The result of converting %ld to binary string is: %s\n", value, str);

    ltoa(value, str, 10);
    printf("The result of converting %ld to decimal string is: %s\n", value, str);

    ltoa(value, str, 16);
    printf("The result of converting %ld to hexadecimal string is: %s\n", value, str);

    return 0;
}

#include <stdio.h>
#include <stdlib.h>

int main()
{
    long long value = 123456789012345LL;
    char str[20];

    lltoa(value, str, 2);
    printf("The result of converting %lld to binary string is: %s\n", value, str);

    lltoa(value, str, 10);
    printf("The result of converting %lld to decimal string is: %s\n", value, str);

    lltoa(value, str, 16);
    printf("The result of converting %lld to hexadecimal string is: %s\n", value, str);

    return 0;
}