Ejemplo de programación del sistema Linux

open_read_write

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    
    
        int fd;
        char buf[32] = "hello";
        int n_write;
        int n_read;
        char readBuf[32];
        memset(readBuf,'\0',32);
        fd = open("./FILE",O_RDWR|O_CREAT,0600);
        if(fd == -1)
        {
    
    
                perror("open");
                exit(1);
        }
        n_write = write(fd,&buf,strlen(buf));

        lseek(fd,SEEK_SET,0);

        n_read =read(fd,&readBuf,strlen(buf));
        printf("read %dBite form write: %s\n",n_read,readBuf);

        close(fd)；
        return 0;
}

Proceso de creación-proceso padre y proceso hijo

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>



int main()
{
    
    
        pid_t pid;
        pid = vfork();

        int fd;
        int cnt = 0;
        char buf[128] = "hello huang hong lei";
        char readBuf[128];
        fd = open("./file",O_RDWR|O_CREAT,0600);
        if(pid == 0)
        {
    
    
                while(1)
                {
    
    
                        write(fd,&buf,sizeof(buf));
                        sleep(1);
                        cnt++;
                        if(cnt == 5)
                        {
    
    
                                printf("child exit\n");
                                exit(0);
                        }
                        printf("cnt:%d\n",cnt);

                }

        }
}

Función de tubería de tubería sin nombre

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>


int main()
{
    
    
        int fd[2];
        int reg;
        pid_t pid;
        reg = pipe(fd);
        char readBuf[32] = {
    
    '\0'};
        char buf[32] = "hello huang hong lei";
        if(reg == -1)
        {
    
    
                perror("pipe");
                exit(1);
        }
        pid = fork();
        if(pid == 0)
        {
    
    
                close(fd[0]);
                write(fd[1],&buf,sizeof(buf));
                exit(0);
        }
        if(pid > 0)
        {
    
    
                wait(NULL);
                close(fd[1]);
                read(fd[0],&readBuf,sizeof(readBuf));
                printf("form child :%s\n",readBuf);
        }
        close(fd[0]);
        close(fd[1]);
        return 0;
}

Pipa famosa FIFO

escribir:

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

int main()
{
    
    
        int fd;

        char buf[32] = "hello huang hong lei";

        fd = open("file",O_WRONLY);

        write(fd,&buf,sizeof(buf));

        close(fd);
        return 0;
}

leer:

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

int main()
{
    
    
        int fd;

        char buf[32] = {
    
    '\0'};
        if(mkfifo("file", 0666) < 0 && errno!=EEXIST)
        {
    
    
                perror("Create FIFO Failed");
        }

        fd = open("file",O_RDONLY);

        read(fd,&buf,sizeof(buf));
        printf("from write: %s\n",buf);
        close(fd);
        return 0;
}       

Señal Singal

#include <signal.h>
#include <stdio.h>

void handler(int sig)
{
    
    
        if(sig == SIGINT)
        {
    
    
                printf("ctrl C\n");
        }
}

int main()
{
    
    

        signal(SIGINT,handler);
        while(1)
        {
    
    
                printf("hello\n");
                sleep(1);
        }
        return 0;
}